I will start off by saying that Onenote is the most useful application that Microsoft has ever created. I do about 90% of my work there, and have been doing so for many, many years. To this day, I have not found an app for note taking that is as fluid and flexible. Thus, any change is viewed with some unease. Why fix things that are not broken? Microsoft have something of a track record of giving users features that they think users need., rather asking users what they actually use. For example. having a huge 'Copilot' icon appear on every line I write is an awkward distraction for a feature that I will never use (did Microsoft not learn anything from the unpopular 'clippy'?).
So, the features mentioned above are fine - but why remove features that are actually useful like the thesaurus?
My biggest fear is that with Microsoft's obsession with AI is that it will not be too long before Onenote is replaced by 'Copilot Note'.