I believe that any company is essentially a paperclip optimizer that will do whatever it takes to win over competition.
AI companies have access to the IP of millions of AI researchers and AI startups who are in direct competition with them. If they can use this data to squash competition (either competition from the same researchers or from others), I believe that they will use it eventually (if not already), even if they say they won't.
They don't have to blatantly steal it - they can just train on it, or pass "suspicous" chats to human inspectors who might eventually be "inspired" by it in their own research. We saw the first (?) hint of this during the brief Fable release, with Anthropic declaring that they will downgrade model responses regarding "frontier AI" (i.e. anything that competes with them).
From other domains, we know for example that Uber used users' ride data to stiffle competition and regulation. There should be no reason to believe that Bigco AI companies won't do the same.