New comment by st3r4g on void-packages repository

https://github.com/void-linux/void-packages/pull/29115#issuecomment-788111562

Comment:
> As for the symlink presence, the concern is really about the guarantees around when alternatives symlinks are present. The dependency graph guarantees that packages, and by extension binaries, will be present but I don't know if alternatives provide those same guarantees in all circumstances.

Pretty sure they do. The alternative is registered (and the symlink created) in the unpack phase, right after package files are unpacked:
https://github.com/void-linux/xbps/blob/01180f9cb60893c4a57935fda106b1d5f77e2b49/lib/package_unpack.c#L663