However, it is important to separate those colleges which were attended by famous actors before they were famous versus after they were famous.
Universities such as Harvard and Yale often accept actors who were already famous in order to boost their own prestige and fame, and have nothing to do with training the actors. So Emma Watson isn’t a famous actress because she attended Brown University, but the opposite - she was accepted to Brown because she was already famous.
So the fact that Jody Foster, Natalie Portman, Reese Witherspoon, Brooke Shields, Julia Stiles, Maggie Gyllenhaal, Jake Gyllenhaal, Emma Watson, etc, attended Ivy league colleges are absolutely no indication that attending these colleges will help a person with their acting career
Of course there are many actors who attended Ivies because they are the kids of famous actors or other celebrities, like Lourdes Leon or Rashida Jones. Since their acting careers were likely helped more by their pater and mater than by their Alma Mater, I would not take these actors as indicators of Ivies being conducive for an acting career either.
There are actors who attended Ivies before they were famous like David Duchovny, Rachel Dratch, or John Legend, but most struggled to succeed as actors just as much as graduates of other colleges.
NYU, USC, UCLA, Northwestern, Julliard, and a few others on that list are meaningful. however, as I noted, I would not consider Harvard to be an especially good college for aspiring actors, nor Yale, Columbia, Dartmouth, or Brown.
That being said, a degree from Harvard may provide a better choice of employment at a better salary for struggling artists, but an undergrad from USC or NYU may be better, John Legend worked as a consultant after college, rather than as a barista, and that may have been because he graduated from UPenn.