There's a reason GitHub is the de facto host for OSS projects, I'd posit that open source maintainers who deliberately choose an unconventional host like GitLab already increase the barrier to contributions (not just due to network effects, but an unfamiliar UI, feature parity, poor performance etc) and this change would've already tipped the balance in my view and made it even clearer GitLab is not the right choice for OSS.

There may have been reasons to do this in the past (e.g. lack of integrated CI) but I'm not convinced those arguments really hold anymore in 2022. If you're a maintainer and prioritising interoperability and the lowest barrier to entry for potential contributors and you don't care about it being proprietary/owned by MSFT you pick GitHub. If you're prioritising a FOSS stack, good tooling offering and low-weight pages with excellent performance, you pick something like SourceHut.

For everyone reliant on software published by maintainers who have already made this decision historically, it's reassuring the right decision has been made here, but a bit worrying they were needing to consider a step this far in the first place. Combined with their poor pay for engineers (discussed to death here on HN already), it does make you think a bit about their finances.