Ole wrote: "Here are the App Store release notes I've prepared for Pythonista 3.3. I intend to submit over the weekend, a pre-release version will be on TestFlight as soon as it's finished processing on Apple's servers."
So the implication seems to be that TF will allow access as a "prerelease" between the time it's submitted and whenever it's (hopefully) approved, but that's purely a guess.