It should be noted that MUL is ever evolving.
The Dragoon was thought extinct in the sourcebook it was introduced and listed so in MUL but ComStar found one anyway. The Shogun is extinct but was put back into production according to 3150NTNU, and its availability in MUL hasn't been updated yet (partially probably because the RS for new variants aren't available).
Of course we don't really know for sure until TRO Golden Century is released and the designs are added to MUL properly.
Yeah, I pretty much said that...
If the MUL says they're extinct, until something new is written, those designs are extinct. All the fan guesswork and what-if's in the world do not change canon. Should a player choose to do something different with their own game, there is nothing stopping them. But that also does not change canon.
Point being, current canon points to them being extinct, period. Fan speculation about future canon is not canon. Players can do what they wish with their own games, nobody is saying they can't, but that still does not change canon.
We're also talking about a Homeworld Clan, and, in my opinion, are quite unlikely to get any solid information on them any time soon.
TRO: Golden Century may flesh out the designs in that era, but what do you think the odds are of any information stretching into the current era? If anything, there may be hooks and loopholes for writers to use in the future, but that still won't be "current" information until it is actually written.
I can confirm that MUL not updated, Turing Points: Tokasha has number new units they included in there either has very little info such as the Fox BattleMech and Minsk, and unites that have been listed yet such as the Kokou Defense Tank, Issedone Light OmniFighter, which clearly have record sheets printed.
So, we're discussing the Fox (Clan Diamond Shark design), Minsk (Clan Ghost Bear design), and Corvis Omni (unknown origin). What information about them contained in
TP: Tokasha will be added to the MUL and state anything about post-Reaving production? I wager nothing.