Are you asking if b3 is the Nimzo-Larsen attack or if it is a strong opening?
In Nimzo-larsen attack b3 , a strong opening used by GMs these days ?

almost anything that's not terrible is playable these days. Engines have done a great job for a lot of openings merely dismissed as inferior in the past.
the mainstream openings still maintain their appeal for best evals and more importantly, more flexibility in variations, but you can see almost anything these days given a whirl at top GM play.

stuff like 1.b3 or the london system (much less the jobava attack) back in the early 2000's was practically unheard in top play except once in a rare while, now no one bats an eye seeing them every so often now. open sicilian used to be religiously followed by white in top games, and yet Carlsen decided to to use the rossolimo multiple times instead at the WO. eccentricities like the pirc and chigorin are more respected now than before even with engines around.
truly, as far as opening experimentation is involved, we are in pretty good times. In the age after Fischer's, opening theory was all about religious adherence too book lines, engines have now humbled us, and we are in an "anything that works, goes" era.

Sure, one off type openings, especially against the bottom seeds, are common, and the focus is just to get a middlegame with chances, not preserve an edge with white. So openings like 1.b3, which more or less immediately give equality, aren't as taboo.
But what Naka plays on stream, in throw away blitz and bullet games... they may be good to study if you want to use them for your own blitz and bullet, but typically questions like the OP's are asked in terms of top tournament praxis.

Sure, one off type openings, especially against the bottom seeds, are common, and the focus is just to get a middlegame with chances, not preserve an edge with white. So openings like 1.b3, which more or less immediately give equality, aren't as taboo.
But what Naka plays on stream, in throw away blitz and bullet games... they may be good to study if you want to use them for your own blitz and bullet, but typically questions like the OP's are asked in terms of top tournament praxis.
have you not seen the 1.b3 renaissance that has been going on the last few years? lots of top gm's now have 1.b3 in their OTB repertoire

Top 10 GMs have practically every opening in their repertoire.
But for example the GRENKE Chess Classic was full of Ruys and QGD as expected. I don't remember one instance of 1.b3.
Not that it's a bad opening.

Top 10 GMs have practically every opening in their repertoire.
But for example the GRENKE Chess Classic was full of Ruys and QGD as expected. I don't remember one instance of 1.b3.
Not that it's a bad opening.
you have to put this into perspective. main line openings are often very rich in variations and opportunities to deviate without risking much, also while keeping optimal evals. off-beat openings often do not have these luxuries and the player must be that much more careful to experiment within an experiment.
in 1.b3's case you are practically free-styling with white (or greatly thinning book at least) but white must be careful and not get Too creative or risk being slightly inferior or worse.
Possibly helpful:
The Nimzo-Larsen Attack: Move by Move (2013)
https://web.archive.org/web/20140627052905/http://www.chesscafe.com/text/hansen175.pdf
"Many opening monographs have enthusiastic titles of the form Winning with the... and invite the reader to ingest some marvellous system or other and rack up points - either by encyclopaedic knowledge of main lines or the methodical application of simple strategies. So let us make it clear, first of all, that White has no advantage in the Nimzo-Larsen. The lines in ECO, for example, conclude mostly in '=' (equal) or 'unclear', with just a few '+=' (White stands slightly better) and even these '+=' seem optimistic. Nor is the Nimzo-Larsen a 'system' opening in which the first moves are played parrot-fashion regardless of the replies. There are system-like elements in some variations - the plan Bb5, Ne5, f2-f4 in the reversed Nimzo-Indian (Chapter 4) for instance - but more often White (and Black) can do just about anything. Anyone who likes to win their games in the opening should therefore look elsewhere." - Byron Jacobs & Jonathan Tait (2001) in Nimzo-Larsen Attack
https://web.archive.org/web/20140626223637/http://www.chesscafe.com/text/hansen27.pdf

Yeah. Nakamura plays it.
This reply is so stupid it hurts.
Maybe its not as good as the main lines, but I was talking about blitz and bullet.

Yeah. Nakamura plays it.
This reply is so stupid it hurts.
Maybe its not as good as the main lines, but I was talking about blitz and bullet.
Sorry to be a jerk about it.

Yeah. Nakamura plays it.
This reply is so stupid it hurts.
Maybe its not as good as the main lines, but I was talking about blitz and bullet.
Sorry to be a jerk about it.
Not a problem.

I know this on GM who used it with good results. He played 93 serious games, losing only 7. His name was Vladimir Bagirov. A name, that for some reason, never gets mentioned when 1.b3 is discussed. It is always Nimzowitsch or Larsen. While Larsen only played 47 games. Anyway, he was also very succesfull using the Alekhine defense as black. But to be succesfull with these openings, they really have to suit you. You have to be quite creative in my opinion. I've tried them both and came to the conclusion i wasn't.

I know this on GM who used it with good results. He played 93 serious games, losing only 7. His name was Vladimir Bagirov. A name, that for some reason, never gets mentioned when 1.b3 is discussed. It is always Nimzowitsch or Larsen. While Larsen only played 47 games. Anyway, he was also very succesfull using the Alekhine defense as black. But to be succesfull with these openings, they really have to suit you. You have to be quite creative in my opinion. I've tried them both and came to the conclusion i wasn't.
Openings are named after the person who popularized them/played them for the first time (at the top level), and openings don't get renamed normally once a name has stuck.
Is Nimzo-larsen attack b3 , a strong opening used by GMs these days ?