Guys that Ao3life takedown form asks for your email registered with Ao3. Which is not public information. The only entity that would have that info besides Ao3 is someone who had breached Ao3. It is 100000% not a legit takedown form, do not engage with it. Report it to Ao3 and/or their domain host.
I know nothing for certain but I'm pretty clicking that ao3life takedown link is a very bad idea, guys, please be careful out there