So far... so good. The game has been advanced to JAN 2, 1983 and the minor league teams with the changed franchise ID all had the team history carry over, while teams that were not changed lost their history.
Even the Geneva Royals history carried with the GenevaNY3 ID. Just had to rename it and switch "Affiliation" from Cubs to Royals under NYPL Game Settings (LEAGUE SETTINGS > LEAGUE & TEAMS).
Will be auto playing forward to next season to see if any issues come up. If not... (fingers crossed) thinking of just manually adjusting each minor league team ID same as was done for all the KCR ml franchise IDs.