Ultimate user here. I assume this doesn't kill "quick answers" for pro users - which I use frequently when I need a quick summarization. For assistant use directly, I've been thinking about stepping back from ultimate, as I use claude for AI rubber ducking; which works better than all of the LLMs available on assistant.
I have maxed out my ultimate usage before and when that happens the quick summarization tools did not function indicating I hit my limit. I assume it would affect those, but that might be part of how they break it up.