My personal guess is that they don't put it in training data, BUT they still have human read what you send, to see 1. what are the innovative uses that they can try to copy/integrate; 2. optimize (both in score and throughput) for their consumer's usage.
if there EULA says one thing and they do another that opens them up to huge liabilities. though anything is possible
Well "huge liabilities"... until recently I haven't seen anything resembling something a company wouldn't just say "pay the fine and do it anyway, it'll be better for our bottom line".