Can I claim that I 'sacrificed' my queen in this game?

I think that counts.

But there is still a sort of a grey area there, isn't it?

a sac is usually when its hard to see the continuation. here its too obvious.

Some people call it a pseudo sacrifice. I don’t think the distinction is really important.

You blundered it - it just so happened you had one last check,, mate!

it's a nice queen sacrifice, only that the outcome was obvious and sadly inevitable

it's a nice queen sacrifice, only that the outcome was obvious and sadly inevitable

Queen is less valuable than king. I don't think this is a sac, since you gain more than you lose

Sure it's a sac, even though it was part of a checkmate combination.

If you need to distinguish what kind of sac. it is, then perhaps there should be a name for unclear sacs that just seem right, maybe a "positional sac." I had two recent games where I sac'd a Bishop and then a Rook in one and a Rook in another.  I overlooked a move in the Bishop sac and was losing until I saw that I had a Dovetail Mate if I tempted my opponent to grab one of my Rooks. He did and I won.  In the other Rook game, I thought I would come out at least even in material and I ended up a Bishop ahead.  The "temptation sac" had a clear ending but the the other two were "hopeful sacs" where I hoped my calculations didn't overlook anything.

Alas chess terminology can be vague and subjective sometimes...

Yes, brah, it is a true sac, congrats!

Mikhail Tal's sacrifices weren't usually tactically justified but he would usually gain enough tempos and space on the board that his sacrifices worked out.

I've seen sacrifice used in ways that would include or exclude this. The distinction is usually whether the compensation is "clear" or not - i.e. you can calculate out a line where the sacrifice is clearly sound.

Personally, I think that definition isn't particularly useful because it then it can depend on the player, not the position on the board.

I would rather call this a sacrifice, and then use adjectives to describe it further (positional, unsound, sound, etc.)

I think most modern books tend to use sacrifice in the broad sense where this qualifies. I have run across older books that want to apply it only when the results cannot be fully calculated. Perhaps one of the differences is the prevalence of engines that can often calculate quite accurately (and deeply) whether a sacrifice was or was not sound.

Sure, you can claim it.  I think a lot of people would be disappointed though to find out that that was what you meant.

I guess I just played one...

I think it counts

If only you were the first one to come up with it...