Islamic scholars consulted by a leading producer of cultivated meat say that the newfangled protein — which is grown from animal cells and doesn’t require animals to be slaughtered — can be halal, or permissible under Muslim law.
And the Jewish Orthodox Union this month certified a strain of lab-grown chicken as kosher for the first time, “marking a significant step forward for the food technology’s acceptance under Jewish dietary law,” as the Times of Israel put it.
I would argue given it is still animal tissue - not cellulose etc - it remains not vegetarian because it is not in any way made of plants. It is, however, not made via animals in any way and thus most people who currently consider themselves vegetarians would probably eat it as most vegetarians are so on moral grounds.