Perhaps, but that I would argue that they may be pushing SNW to be relocated for two possibilities.
1.) Gate IV would've featured more digital based attractions compared to practical attractions.
2.) While they have IP's that could get people in, they don't have as big of a Potter IP. While I won't disrespect the notoriety of Jurassic Park and Fantastic Beasts, one just got a new film since 2001, and the second is dealing with not only new territory; but that it somewhat alienated audiences.
Just guesses on my part, but that they may be wanting to ensure the fourth gate is an automatic hit; and having Nintendo's first wave hit Florida at the fourth gate would bring people there more than it just being an expansion.