I agree junior leagues, women's teams may require a huge amount of work and time, but not so sure about Utopia. It would be just another country, certainly with slightly changed rules and restrictions, but still, would that be so hard to implement? But I don't know anything about programming in this game, I could possibly be wrong.
It appears I'm not the only who likes Utopia's idea. There are also a number of managers who would prefer their second teams to be able to compete in other nations. So another poll to find out the distribution of votes would be interesting.
Just a hypothetical example that is almost assuredly not correct but a representative sample of something that could be unforeseen because of some assumptions the coders made that Utopia would change.
Let's assume that we add a new country "Utopia". Let's further assume that the end of season update script does, among other things, manually resets the appropriate NT/U21 enthusiasm to the proper level, starts up the election and so forth. Now, Utopia does not have a NT/U21 because it's not designed to do so, and so the update reaches that part of the script, explodes, and the processing stops. If the update is truly just scripts repeated each time for each of BB's nations, that's something entirely possible and suddenly would require a whole new set of processing be coded for Utopia. Or perhaps, the code is separated enough that it's possible to specify not to run a U21/NT script for that nation, but perhaps that part of the script also handles aging up the players to ensure that the old players are no longer eligible.
Point being, we don't know how tightly or loosely coupled the code is, but if the game was designed on the notion of every country being the same, suddenly shoehorning in a new country with different rules can be very disruptive. And when there's a reasonably good alternative solution that uses existing teams and existing leagues, which also gives some competition to micronations (which anyone who's read Wolph's volumes of literature on the subject may appreciate), it makes little sense to make massive alterations.