No need to look for a conspiracy, this sort of thing happens all the time to all sorts of companies. Maybe it's a patent they want, maybe they want the talent, maybe they want the assets, maybe they want to remove a competitor... It's really not that unusual.

Maybe they want to suck part of the codebase into notion?

I have a friend who works with ex Zenly employees, and that's exactly what Snapchat did with them.

Just buying the tech. Might want to use it internally or whatever