The only answer anyone can give you here is that that sounds like an unfortunate glitch, and perhaps some really poor programming/planning in some area, but no,

The only answer anyone can give you here is that that sounds like an unfortunate glitch, and perhaps some really poor programming/planning in some area, but no, destroying your notes is not an effort to onboard you to the paid version. “What happened to them” is covered in other comments (same thing that’s happened to everything that isn’t dominated by a benevolent vision-possessing dictator of sorts to keep things focused and say no a lot).