Hi @Asday, and welcome!
See
Packages only end up in stable when they’ve been vetted and then promoted from unstable to testing and, finally, stable. So, in other words, just be patient. This is the curated part of Curated rolling release.
AFAIK not only that package, or at least I don’t know how if possible, but you can always switch branches, upgrade and then switch back.
But be warned: Since packages in the unstable branch have not yet been vetted, there exists the chance that you might experience breakage. You have been warned.