I can soften it, but I think you're reading it excessively negatively: that warning is there to make sure people don't try to do the fiddly, error-prone cryptographic bits if they don't need to. It's a numerical fact that most project owners don't need that section, since most are either using manual API tokens or are publishing via GitHub Actions.
> Perhaps also add a few of the providers you listed as well?
They'll be added when they're enabled. Like I said in the original comment, we're using a similar enablement pattern as happened with Trusted Publishing: GitHub was enabled first because it represents the majority of publishing traffic, followed by GitLab and the others.
> GitHub being popular is a self-reinforcing process, if GitHub is your first class citizen for something as crucial as trusted publishing then projects on GitHub will see a higher adoption and become the de-facto "secure choice".
I agree, but I don't think this is PyPI's problem to solve. From a security perspective, PyPI should prioritize the platforms where the traffic is.
(I'll note that GitLab has been supported by Trusted Publishing for a while now, and they could make the publishing workflow more of a first class citizen, the way it is on GHA.)