If we take your Wordstar 4.0 example literally, it's not a good example of the concept I think you're trying to convey. Wordstar did change for 7+ versions after 4.0: https://en.wikipedia.org/wiki/WordStar#Version_list
Wordstar didn't freeze at 4.0. Instead, what happened was George R. R. Martin's idiosyncratic usage of word processing froze at WS 4.0. That's a very different concept.
If we define "finished software" as determined by the end-user instead of the developer, then any software of any version that doesn't force auto-updates (e.g. not Chrome, not Skype) can also be "finished" if the particular user is satisfied with that old version. E.g. In that mental framework, Adobe CS6 from 2012 and Windows 95 can also be "finished software" because the user doesn't need/want Adobe CC 2023 and Windows 11.
Maybe a better example of "finished software" from the perspective of developer would be a one-off game where the programmer never had intentions of making franchise sequels out of it.