I've been half off facebook for a long time now and "deleted" all my content 6-7 years back.. I don't think its actually been deleted though.. I wasn't expecting to find much but did notice some strange/interesting things --
i see 'active sessions' for Nov 2018 onwards, but logins for may 2018 onwards..
theres a 'watched videos' category which i never noticed before, goes back till June 2015. I hadn't seen it when i did the purge so didn't delete it, but really deleting is just hiding it from your self
heres some funny pictures ..
Updates : I later downloaded all the data, and confirmed that nothing was actually deleted, despite it not showing up on the web interface. The downloaded data is far more detailed.. how nice of facebook to give the illusion that one is seeing everything on the web interface..