My guess is as good as anyone’s but here:
He had a major lead in life and was one round behind. He saves his meter for the hypotethic 3rd round instead of going for a little more damage in that punish for a round he almost had (this would almost prove bad after fei landed that ultra but he still came back).
That decision made sense and IMO is proper meter usage.
Consider a more extreme scenario that will highlight this:
First round, you have 5% life, your opponent has 100%, imagine, for whathever reason, you have no ultra to spare. Your opponent does a dumb jump in and you RJ, will you cancel to add a tiny bit more damage or will you try to build some meter for the next round, as it seems unlikely you will win this one?
Of course when you add the damage an ultra would do the decision is a little bit different. He tad no ultra though.