I just simmed to the reset date for Mexico which is June 10. No teams got promoted. I also simmed for 3 more years because of average points. No teams got promoted still.
Upon further digging, promotion/relegation with Liga MX and Liga de Expansión MX has been suspended.
Tampico Madero, the club I managed in FM23 for this challenge, won Liga Premier which should've granted them promotion to Liga de Expansión MX. Atlante who won Liga de Expansión MX should've been promoted to Liga Mx. They got certified for promotion but they didn't get promoted. It seems like four teams have to get certified for promotion to happen in which that their financials and infrastructure are good.
I guess that makes it nobody is going to get promoted in the Mexican leagues.