In theory. In practice, a lot of the militias and militiamen are still largely independent.
https://globalriskinsights.com/2018/12/challenge-far-right-ukrainian-militias/
I know at least one person from _each_ of the independent militia groups that were operating in 2014. I know some ppl from groups called in this article "neo-nazi" and I find most of the article laughable. One can't call civil group "militia", militia is an armed group. There's so much wrong in this article but this will be total off topic to discuss the article. So I won't. Let's talk about guns.
"Officially issued" has nothing to do with it. When the situation went pear shaped in the Ukraine, armories ad stockpiles were broken into and raided, with or without the assistance of the forces that were supposed to be guarding them. Typical of any civil war (or at least, a war the Russians would prefer people think is a civil war), if it goes bang reliably, people are going to grab it and use it. It doesn't take any time at all to come across plenty of images from reliable news outlets (Reuters etc.) of combatants from both sides using SKS's and MN's. And the security situation in eastern Ukraine is bad enough, that even non-combatants are grabbing up whatever small arms they can for personal defense.
Regardless, it doesn't really matter who's using them or grabbing them. Small arms and ammo aren't leaving the Ukraine for the foreseeable future.
You're making too broad conclusions from limited number of facts. Only some police departments were raided, their armories had Makarovs and AK (mainly AKSU) Consider following sources for pictures during initial stage of confict: private guns, reactivated guns, dewats and AK airsoft guns too were used by separatists on road blocks. All this chit was abandoned after first fights and there were no shortage of AKs and modern MGs for any side since then.
Exceptions are dozen of reworked MN snipers (abandoned project) and some number of Maxim MGs currently used, they have very interesting reason to use it.
As for private guns just in case - you underestimate Ukrainians. As captured guns are not accounted all my friends have at least PM, many have Stechkins they are more desirable - this is "for home defense" and "just in case" choice is usually AKMSU or even RPKs in some cases

Again, nothing of it we can import. Nobody needs SKSs and MNs, I can assure you. If one is very concern about legality - he buys legal converted auto AK and couple of spare parts to make it back select auto. Sound moderators are legal too BTW.
And you're wrong, as I mentioned before Ukraine has been offering military surplus, I won't publish price lists, I don't think it's appropriate. Dealers had offers, they did not liked prices. That's all I can comment on this. There are also openly available yearly reports so everyone could see what guns were sold by Ukraine to which country.