No. 2 points is a lot at that level. If the commentator would think a move cost 2 points he wouldn't call it conversative but he would call it an error.

I think B actually results in more points overall, which is why it would play it; my curiosity is what fraction is due to direct effects vs. indirect effects.

For example, one could imagine the board position evaluation function being different for different timing schemes. If you're playing a blitz game where both players have 10 seconds to play each turn, some positions might move from mildly favoring black to strongly favoring black because white needs to do a bunch of thinking to navigate the game tree successfully.