First, don't ever rely on surplus ammo. It's here today, tomorrow it's nowhere to be found.
Here's my view on why you will never see a general purpose "for the consumer" new tokarev carbine.
Manufacturers aren't going to rely on cheap surplus ammo for sales of their new carbine. 9mm, 40sw, and 45acp cover the niche effectively. There's nothing practically that the 7.62x25 tokarev round can do that the previous three popular rounds won't do.
I believe the main reason for the cheapness of the tokarev round is because there may be very few buyers. I think it's accurate to say that people buy the CZ52's and PPSH41 semi auto for collecting purposes, not for serious business like defense or hunting, STHF, etc.. And not everybody is a collector either. Some people, if they want a weapon in a pistol caliber, will often go for 9mm, 40, or 45 because there's more choices. Those 3 rounds are also FAR easier to come by. In my experience, 7.62x25mm even brand new brass cased ammo is not common in gun stores, and especially sporting good stores.
If anything, we might see some conversions if there's enough demand. An upper for an AR15 perhaps? etc etc etc....
It's just that some calibers will die out eventually because either there wasn't room for them in the market, or there were initially not enough appealing weapons in that chambering, or everybody moved on to standardizing. The 7.62x39mm is a unique cartridge in that the US never had an equivalent in a battle weapon. With all those ak and sks rifles that came in and made the round popular, it stuck with us. Will the 5.45mm last for another 5 years? I doubt it. We already have the 5.56mm and all new combat weapons coming out in the world and in the US civilian market are always in 5.56mm.
Going off topic, I'll stop here.