The founder of Impossible Burger was on Too Embarrassed To Ask podcast [0] and I specifically remember him talking about how his product is meat (because of the heme). It's just not meat from an animal, or at least this is how I interpreted sections like "...It’s a heme protein that turns out to be basically the single thing that separates meat categorically from all other foods in terms of its flavor profile."

0 - https://www.recode.net/2017/8/18/16171336/transcript-impossi...