Context: Real Meat That Vegetarians Can Eat
If the reason for not eating meat is purely ethical, then consuming simulated meat bears no moral consequence whatsoever to a person committed to a position that all plausibly sentient life is sacred, that all manifestations of embodied experience and awareness are a difference of degree, not of kind.
However, people (as we know) are far more complex than simply-asserted linear or logical threads of inference might suggest. Why does a person attach themselves to an idea of vegetarianism, of veganism? The question can be misleading as it is at base a question of why persons, tribal affilitations or entire social and political movements become attached (to the core, self-gravitational object of) a belief in any idea around, through and by which they then reflexively identify and validate themselves.
Systems of belief are dissociative, anchored upon tautologically circular self-validations. A strong position on the core ethics of not eating meat in any circumstances is quite likely to persist in many, regardless of the provenance of that protein. The symbol of “thou shalt not” as axiom and foundational negation in or as (a) belief system and psychological self