It’s not a new trend. Lakewood mesivtas that aren’t the Cheder only started popping up in the last 15 years or so. The first ones to start emulated the Cheder and followed vague apocryphal out-of-context sayings of Rav Aharon Kotler ZT”L so they didn’t have English. Every subsequent mesivta to open up was too afraid of being “der modernische platz” that no one would dare send their kids to, so they didn’t open English departments either.
Everyone wants their son to be a gadol in limud and sit in klei kodesh for life. But if you understand that the world isn’t perfect and your child may need to actually have a parnossa for himself, and still not be ostracized from the community, you’ve got to send to an out of L’Wood mesivta, like Brooklyn, Cleveland, or Philly.