If we want to get even more pedantic (which I thoroughly enjoy lol), we can even point out that Nixon used the phrase “last version of windows” to mean the “latest version” or “the last version to have been released to date”.

This is in a similar grammatical sense as staying “last week” or “last Wednesday”. Last week wasn’t the last week to have ever existed. Last Wednesday wasn’t the last Wednesday to have ever existed, either. And windows 10 wasn’t the last windows version to ever be released… it was just the latest (or, “last”) version as of the time Nixon said it.