I think that's much more true of large companies than small ones. At a small company, the engineers are more likely to be involved in the hiring process, and (unless they're very inexperienced themselves) they'll have a better sense for how skills translate.
For example, on my team, we're writing most of our new code in Kotlin. But even though the language has now been around for the better part of a decade, we regard prior Kotlin experience as only a very slight nice-to-have when we're evaluating someone. If you've programmed in Java or Scala or C# or C++ or pretty much any other statically-typed language, you'll pick it up quickly enough that the time to get productive in Kotlin will be dwarfed by the time to get familiar with our code base.
What we do usually filter out, though, is monoglots. If you have 10 years of experience and have only ever done, say, Ruby on Rails development, you will probably not have the breadth of engineering perspective to succeed on our team. But if you've done RoR as well as something else that's dramatically different, that's fine. We would probably even filter out a Kotlin monoglot in the unlikely event we ever came across one.