It won't be accepted. If anything it probably will be treated like veganism, which is mostly moral grandstanding. People who consume boutique products to show their virtue. A lot of us simply don't lose sleep over the suffering of factory animals, in the same way we didn't lose sleep over the starving kids in china our mothers used to berate us about when we didn't finish our vegetables. That doesn't mean we constantly try to make things like a hellscape, but you can try and treat everyone morally and not get in a tizzy over "someone is being oppressed somewhere! See! Our moral guardians of the media are showing us!" The idea of telescopic philanthropy and being a Mrs Jellyby needs to be remembered.

If it got to the point where it was mandated, we'd probably be in some form of dystopia where everything was in the pursuit of either survival (animals no longer exist or are possible to eat) or sort of a planned world where our governing or elite classes mandate their virtue on everyone, and it would lead to a lot more lifestyle changing that not eating meat. I think the latter is fairly likely, China for example seems to be doing pretty well at a basic form of that.