My thought is that while the Kaepernick movement has suffered a lot of signal loss in the last week, what happened is much better than what could've happened (like the GOP-donating NFL owners closing ranks and making anyone who knelt know that they'd suffer the same fate as Kaep).
Yeah. I think this is what Trump expected to happen, and he's upset it isn't which is why he's also rambling about it being made a rule to stand.
Then, he saw the people standing in protest and tried to claim that, so as to eke out some kind of win in the situation.