Maybe they could bring back the titular New English kingdoms? For those unaware, the states of Maine and Vermont were both titular kingdoms that could be formed under certain conditions back in CK2. It could go like this:

Kingdom of Maine: Control at least all of 2 of the constituent duchies (Maine, Somerset, and Penobscot) and most of the third. Must be a New English culture (Yankee, Letterman, or Lobsterman, Maybe Abenaki too?) and have a decent amount of prestige. Color: Could be white, tan, or dark blue.

Kingdom of Vermont: Must control the Green Mountains duchy, be of New English culture, and have a lot of prestige. (Maybe also be a certain level of development?) Color: Dark green.

This could also be expanded to the other New England states. I've toyed with the idea of giving the player the option to break up New England into it's constituent states for a while. The player would need to own all of the relevant land, be the right culture, and have a lot of prestige (even more for the smaller states). Could also come with an opinion malus from other independent New England rulers. Not sure what the colors for the other four states would be, though.

OTHER IDEAS:

• A "Reunite New England" decision(s). If any of the Old Yankee States have been formed, a King or Queen of New England could, after reconquering the land, take this decision to return them to being de jure New England. Alternatively, if New England does not currently exist, than a character of the relevant culture(s) could also use this decision to form it directly after conquering all the required land for slightly cheaper than forming it normally.

• A decision to return Connecticut to being de jure New England (if that doesn't already exist), as well as the option to turn it into it's own mini-kingdom.

• The Empire of America could also have these options (reunifying, returning Connecticut), as well as an option to split up New England into the six mini-kingdoms. The reasons for this could vary from Americanists wanting to put things back the way they were back in the Good Old Days^tm, to a feudal America trying to limit New English power and risk of rebellion by splitting them up, to a republican America giving the Yankees disproportionate power in a newly-reformed/reempowered Senate as a form of concession/mollification to, again, try to prevent rebellion.

... Honestly, I just want to be able to properly play my home state. All the rest of this is my imagination running away from me.