“It was a general comment as most reputable graduate/professional programs not only need an undergrad degree but in top of it, work experience, internships,GMAT, GRE, MCAT, LSAT etc.”
Not to be nitpicky, but again, you are stating incorrect information. First, MFA programs - including extremely prestigious ones such as Juilliard, Yale, etc - as well as the British graduate programs, do not typically ask for GREs. MFA programs - which is what graduate acting programs are - care about the audition first and foremost, then your experience, letters of recommendation, personal essays etc. Your undergraduate major is not terribly important, unless you are applying directly upon graduation (which is not typical), and even there you dont’ necessarily have to major in acting.
On very, very rare occasions you can indeed be accepted into an MFA program without an undergraduate degree. This would be when your life experience is exceptional. This doesn’t necessarily apply to celebs; it can apply to a veteran, or someone who has been in prison, etc. People whose life paths are not ‘typical’ but who demonstrate great promise. But in the vast majority of cases you need an undergraduate degree in order to pursue your graduate degree.