Sometimes we have a beta package that has never GA'd - so if we run the release with Skip.PublishVcpkg = false (i.e. as normal), it will create a PR at https://github.com/microsoft/vcpkg/ (official vcpkg repo).

This is what we need almost always, but there have been cases when we couldn't do that - if that package depends on a feature that is only present in beta version of Core, we of course can create the PR for the vcpkg official repo, but it will fail in the CI, because post-GA beta versions are not present there. So, this must be slightly noisy for the vcpkg team to review such PR, plus we probably need to go there and comment "please close this PR", or "this is expected to fail until next month".

Your other option to not create a PR is to run with Skip.PublishVcpkg = true, but then the beta registry won't be updated either, and we'll need to update it by hand ourselves.

I propose to add Skip.PublishVcpkgOfficialPR run flag - when it is set and is true, we do everything as usual - we even create a branch, but we don't publish the PR to the official vcpkg repo.

(the name could be SkipPublishVcpkgOfficialPR or anthing else - it is not that important)

I think we need the branch to be created and not skip the step entirely, so that when the next month that Beta of Core that the package depends on becomes GA and is published in the official vcpkg repo, we can easily create a PR from that branch that was created a month earlier (or we can merge it to the same branch that updates core; or next month we could set VcpkgForkBranchName to be this branch that was created a month ago, and it will get published - there are several options available).