I wouldn't be surprised if higher-end restaurants end up lagging on this trend, simply because they have a bit of a reputational hole to dig themselves out of w

I wouldn't be surprised if higher-end restaurants end up lagging on this trend, simply because they have a bit of a reputational hole to dig themselves out of with the vegetarian, and particularly vegan, crowd. For a lot of reasons. For starters, the options a lot of higher-end restaurants offer have a history of tending to be either really unsatisfying "twigs and berries" type food, overly rich (a lot of vegans aren't used to having their food drenched in cooking fats), poorly prepared (e.g., overcooked), or a mix of them all. So there's a long history of being charged what feels like a rather exorbitant price considering that you end up going home hungry and dissatisfied. Second, vegetarians do notice and make decisions based on what non-vegetarian options are on the menu. If you're serving veal or foie gras, the vegan member of the party is going to be a lot more likely to try and convince the rest of their party to go somewhere else. Also, straight-up boredom. People who eat vegan in particular tend to get really into cuisine from all over the world, and become acclimatized to eating food that's got very bold flavors. After a few years of that, the nouvelle cuisine-inspired stuff being served at a lot of higher-end restaurants is, frankly, just not very exciting. Especially after you take out the butter and cream and whatnot that serve as the gastronomic foundation of that style of cooking. Which isn't to say that all high-end restaurants are like that. But so many are that eventually it gets easier to just use the price point itself as a heuristic.