Even if you think animal suffering doesn't matter, consider: If they're this sloppy now during early research, are they suddenly going to clean up their act once they're selling product to humans?
How many consent decrees have Musk and his companies violated? I think the chance of Neuralink following FDA rules is low, even after any hypothetical lawsuit ordering them to follow the rules. To make an omelette you have to break a few eggs, and Musk has giant huevos.