This version can be the base for RTM, but never be the RTM version. This is an Insider/beta version, period.
If the rumors and factual findings are correct then this is the base for the final release in autumn 2022 but msft will always keep the designation insider preview till they decide to go GA. This is not a dev channel level insider preview so not a real test version as in there.
I hope the rumors are true, because these versions are different from the "RTM/Final" versions. even with language packs. For my native language even with language packs. Are different. First is not fully translated. shortcuts are diferent, for example: select all is "ctrl+a", even with language pack. In my native language, "Final version" or RTM, select all is "ctrl+t". among other differences.
Because Insider versions doesn't exist in my language. I can use language pack, but is not the same. because of the problems I mentioned in the posts above "difference on shortcuts, lack of translation and other things"