It’s not libel. Defamation requires a false statement of fact. Marking a website as “unsafe” is an opinion.
The problem is that these gatekeepers of the internet respond to false statements of facts/opinions by so called professionals.
I had cloudflare mark a worker as phishing because a AI "security company" thought my 301 redirect to their clients website was somehow malicious. (url redirects are normal affiliate things)
If the professionals don't understand the difference and cloudflare and google blindly block things, this is scary.
That is more than an opinion. Chrome has a monopoly and should act accordingly. Blocking entry to a website should be a last resort, not just because someone didn't add their website to the whitelist.
I get that's mostly what corporate lawyers argue about, but it's functionally dishonest in this case.