AFAIC its up to the Russians whether they want to recognize the current government as legitimate or not.
I know for a fact they didn't recognize the Maidan radicals as legitimate and the notion that they were somehow bound by a twenty year old memorandum, after the same radicals broke a power sharing reform agreement they had just signed is risible.
I truly believe the Russians have a soft spot in their hearts for the Ukrainians otherwise they'd have stomped them flat by now.
Russia wants to work with Ukraine.. of that there is no doubt.... All this is about preventing Russia’s influence and obtain Ukraine within the Eu/US influence. Doesn’t really matter what the people want...it’s going to play out where both Russia and the Eu/US win and the people loose in the long run.