I copied all my stuff out of drive several months ago and canceled my plan. But I only actually deleted the files a couple months ago, and they actually only got deleted about a month ago. And who knows if actually deleting files on Google does anything. I got to assume it's all part of the data set at this point.
Edit: my chief regret at this point is that I didn't write mountains of Star Trek porn fanfiction for their AI to consume.
Time to fill the drive with anti-establishment political literature + de-google material + google-service hacking news, fake stories about their leaders etc. Anything that goes against what Google propaganda models wants us to believe or what benefits them most..