They did fuck all with Karelia after they took it so I doubt Donbass would be any different.I sometimes wonder - and I'm not really into this and it shouldn't happen, but I still wonder because the country I grew up in faced something like this - what would happen if Ukraine gave up on the south/east and say "we lost" and the west would marshall-plan the rest of Ukraine into a "proper" european country and rebuild everything while Russia will most likely struggle to rebuild the infrastructure in the occupied regions since they basically destroyed 90%+ of it.
I'm just trying to imagine how Russia would obviously try to pump money in there as well to not lose to the "West", just like the Soviets did in East Germany (which was still pathetic, relatively - so pathetic that we still spend money to equalize the west and east).. money they probably won't have because the sanctions won't stop. Formerly important industry such as the Azovstal steel works are completely destroyed anyway... in fact, they are already planing to demolish it.. or what is left of it.
Would Russia accept the status quo when Ukraine would say "okay, you get to keep the regions you conquered, but since you are not to be trusted, we will join NATO/EU"
And if they don't, wouldn't that officially and completely destroy the picture of their propaganda machine that tells people that they are not trying to invade a sovereign country and all that non-sense?