If you're not going to trust them when they say "here is a contract that guarantees we won't train on your data" because they trained on a scrape of the web, you're never going to get the benefit from these tools. I guess that's your call. I chose to believe companies when they contractually oblige themselves to not do things.
>>simonw+(OP)
Microsoft and Google are of course both famously known for studiously obeying contracts, the law, and not stabbing their partners in the back when it goes against their monetary interests