Kiev can't reclaim rebel Donbass without the help of Russia, but there isn't and will likely never be a Ukrainian politician self-assured enough to take the political risk of granting Donbass autonomy to do it, and Kremlin for its own domestic political reasons can't push the rebels under Kiev without it, even if it wanted to.
That makes Minsk dead, under Zelensky as much as under Poroshenko. Moscow likely held off on the citizenship/passport decision to avoid unnecessarily boosting Poroshenko in the election, but that it didn't even wait for Zelensky to be sworn in, goes to show it understands the latter isn't fundamentally different. In reality Zelensky shares the exact same nationalist approach on East Ukraine, he just focused on the economy and corruption more — something that Poroshenko who had failed on these two could not do.
Russia had previously allowed residents of Abkhazia and South Ossetia which had broken away from Georgia to seek Russian passports (and thus citizenship) on the grounds that they were otherwise unable to travel and isolated from the world in their tiny ethnic enclaves. It took nearly five years but finally it could scarcely do less for its own Russians-Ukrainians of rebel East Ukraine.