It's easy to copy things into your own overlay IF you get notice that this version is going away.

Rarely, you might need to keep a dependency around. But no, usually the earlier packages still build just fine for a very long time. In the case of a high-churn package like chromium, there is a reason to be on latest - all the security patches - but when the latest doesn't build, the previous one is already gone (and would have built just fine.)