I can remember a similar situation (concerning MLB) with the Chicago White Sox. If my memory serves me properly, that team threatened to move to Florida if a replacement for old Comiskey Park was not built and other issues addressed. That I guess is one main reason why the old park was torn down and replaced by the current one and also MLB expanding to Miami and Tampa Bay when they did.
Even in the 1970s, there was a plan to move the White Sox to Seattle and the A’s to Chicago (where Charlie Finley lived) to replace them. the thinking was that that would get the A’s out of a bad situation, buy off Seattle (which was suing MLB over the loss of the Seattle Pilots), and solve the White Sox problems too.
It didn’t work out for a variety of reasons.
Then the White Sox made noise about moving down to the then-Suncoast Dome (now Tropicana Field), and they got their new ballpark.
The giants, at various times in the 1970s and 1980s, were going to move to Toronto, Tampa, and Washington.
The Athletics hve been threatening to move everywhere from Dallas-Fort Worth to Seattle to Sacramento to Louisville to Miami to Washington. Some of those options are no longer available.