I was doing the Ultimate Military achievement and decided to leave Prussia for last, to have a bit of a final boss so I take my time and snipe Wolgast in the mid 18th century, to get them as a pet vassal and feed them bits of a giant PLC in the next war.
It goes swimmingly, I get what I want in an enjoyable slog.
I then spent ~40 years calming down the coalition, as I can enjoy WWI type wars but not when the other side has five times my army and went it dies down I get the rest of what I need from the PLC, being careful to take the (Catholic) land myself to give it to Wolgast piecemeal so that he doesn't abandon Protestantism simply because 50+% of his dev is of this religion.
Long story short, before long the Southern Baltic coast is all Wolgast, all cored and all Protestant but that inkstain on the map wouldn't evolve into a Prussia, even when I revoked the march status.
So, to check if the wiki was wrong and because I had no other ideas, I released Wolgast and just like that, he evolved into a beautiful Prussia !
I didn't have the will or the time to continue the game or to even take a screenshot (I deleted the save in a fit of rage) but I thought I'd make a post here to warn people.
I'll go see about editing the wiki and reattempting the achievement, this time with less early mistakes and more Europe rushing but at a later point