The Rock and his brother-in-law may be to blame
While he doesn't give specifics, Tyrese claims that The Rock is making the franchise "about [HIM]," and that his brother-in-law, Hiram Garcia -- the president of production/film for The Rock and Dany Garcia's Seven Bucks Productions -- shares the blame.
If you don't read the trades, The Rock and ex-wife/business partner/manager Dany Garcia formed Seven Bucks Prods. in 2012 to hasten the former professional wrestler's takeover of mainstream entertainment. Dany's brother, Hiram, now plays an instrumental role in ensuring The Rock becomes unavoidable to virtually every American, thanks to big-budget movies like Baywatch, the Fast films starring The Rock as Hobbs, and the upcoming Jumanji reboot, among others.
In short, Hiram and The Rock run shit. And Tyrese is pissed that they're allegedly holding up the next movie by a year, calling it "another #BayWatch," a reference to The Rock's disappointing 2017 summer film.