I came to the forum to start a conversation about this that I thought you’d want to comment on @karlnyhus given your own use of NotePlan, and I see you beat me to it 
I’m not keen on NotePlan seeming to be transitioning more to PKM than task manager - it’s value to me is that it’s one of very few markdown/plain text notes-based task managers, and I’m not keen on the app losing sight of that (I.e. it’s not Obsidian).
But, this opens up interesting uses for its ongoing role (for me) as a scratchpad alongside task manager. I leave NotePlan open to the side of my screen much of the day (mostly just because I have the real estate to do so, I have an ultra wide monitor with a portion of desktop that I rarely use), and I regularly jot down fragments of thoughts so that I don’t lose track of stuff while I’m doing something else. This new Open AI integration could speed up the processing of some of these fragments (e.g. if I need to make a proper note about something, or write a new set of tasks around an issue I’ve spotted). I am also superficially impressed by the simple markdown table creation that was demonstrated!
However, I don’t know if I’ll actually use the AI, and I don’t agree with some of the use cases demonstrated in the video by NotePlan here. We’ve discussed the ethical issues around using AI for content production and we’ve discussed disclaimers for written material. People expect that if they’ve received a personal message from someone, it was written by the individual, not AI. I think this is a slippery slope that will likely devalue written communication 
(And given that for most office workers written communication is the main way we talk to others, this seems not a great path to go down.)
I’m still thinking through my thoughts around AI, but I’m starting to feel there is a very clear boundary forming between “AI for my own use” versus “AI that will venture beyond my personal domain”. So in the context of the NotePlan demonstration, AI to format a markdown table or tidy up some notes for myself is fine, but AI to write an email or an article still has ethical issues.
[Given the topic, I feel I should add a disclaimer that these are my own rambling writings and weren’t written by AI, which would probably have been more succinct 
]