You could just add an entry at the top of "teams" with "ignore team" set to "specific team" and the new team (before the standard "get all teams from division" entry or whatever it is). Add an "end year" for that rule, of the first season, and it won't use it anymore.
It's not pretty mind you, the game/your board doesn't really know what's going on and might try to set expectations, transfer budgets, etc. You could add a transfer ban for that one club until a few months before the season starts, I guess. The way MLS does it (with "next divsion") seems hard-coded and not easily replicated