Are you referring to "new rules" taught in English classes? I'm curious as to what they are.

Commas are not needed if one wants to use "and" repeatedly:

"The music was great, but we left because the venue was boomy and hot and humid and crowded and too dark."

Otherwise, I believe multiple commas are still correct written English:

"The music was great, but we left because the venue was boomy, hot, humid, crowded and too dark."