Dreev is renowned to be a great theorician...
Is the Grunfeld 5.Bd2 a good repertoire choice?

Yeah, Dreev and even Svidler has played it.
If we accept that there's no line that gives White an edge against best play, and that a serious Grunfeld player has to spend a huge amount of time studying and learning how to play against the main lines, then Bd2 becomes a reasonable repertoire choice if you aren't trying to break 2700.
I'm thinking about making 5.Bd2 the line I play exclusively against the Grunfeld, but I'd like to know if it is a good choice, especially as it seems to be somewhat rare (though Dreev has a fair number of games with it).