When I spawn villagers using vanilla spawn egg or install MCA mod over a save with vanilla villagers, the villagers in green clothes added in the 1.8 version don't turn into MCA villagers.

Minecraft 1.12.2
MCA-1.12.x-5.3.1-universal
PadixCore-1.12.x-2.2.1-universal

P.S. Sorry for spelling and/or grammatical mistakes, English is not my native language and I have some problems with articles

I think this happens because green-robed villagers aren't "real" villagers, they're "dummy" villagers that have no profession and can't be traded with. I just sort of treat them like the village idiot, which makes them sort of special actually, because they're pretty rare! I named them with name tags, hehe...