Hypothetically speaking, if Falcon 40B could out-perform GPT-3.5, would that force OpenAI to open-source GPT-3.5?
There no reason, particularly, to believe either that it does, or it would.
For openai to scramble and try to “catch up” with a competitor and make such a massive change in strategy would require someone to be offering an equivalent service (hosted inference) that was either orders of magnitude cheaper than their offering and just as good, or significantly better than it. Or legal compulsion.
This is none of those things. They won’t care.
I had previously assumed it was safety concerns, since I don't see what stops someone from finetuning away all guard rails.