The back of a package of Upton’s chorizo seitan says “vegan & plant-based”. I’ve talked with a couple people about this before: plant-based isn’t inherently vegan, but there are only a very select few implausible ways to get food that’s (varying degrees of debatably) vegan and not plant-based. We’re talking, like, accidental roadkill, a hamburger you found in the trash, an animal killed in a dire survival situation… (Edit: Okay, I guess pure salt as a meal also applies.)
So Upton’s, I’m really glad you reassured me that it’s both.
We do normally eat rocks; we literally need the flavour rock to live.
No, I get that, but few people are going around eating pure salt in appreciable quantities, and plant-based food with a non-life-threatening proportion of salt mixed in is still plant-based (see, e.g., soy sauce, whose proportion actually can be life-threatening). When I said “we don’t normally eat rocks”, the implication was “we don’t normally eat rocks as a meal unto themselves”.
The broader point being that edge cases for “vegan and not plant-based” food are functionally non-existent.