Why would this make Cloudflare appear remotely trustworthy?
And we're definitely not talking about small amounts. Cloudflare violating it would result in Mozilla violating the privacy of millions, which can be interpreted as significant damages to the citizens. They're also both situated in California, so privacy will be valued by a judge. Given Mozilla's public image as a privacy-friendly organization, they could also push charges for damaging that image.
That penalty + the damage to Cloudflare's own reputation, I cannot imagine they would survive.
IANAL but it looks like extreme weasel wording (and not even remotely GDPR compliant), there is nothing to violate.
> Cloudflare will also collect and store the following information as part of its permanent logs. [...]
- Aggregate list of all domain names requested
So while they might not associate it with a person, they will collect all domain names they get and store them for their own purposes.