Well, I (and Privacy Guides) always advocate for “technical” guarantees over “policy” guarantees. If Proton controls your network infrastructure from end to end, I think it’s fair to simply point out that you’re not protected from them attacking your network.
Proton generally agrees, which is why they say:
While we continue to push the legal and policy frameworks in our community’s interest, ultimately, the best protection we can provide users is through the laws of mathematics, which are unyielding and unchanging. Today, the privacy by default provided by Proton’s products is derived primarily from our usage of zero-access encryption and end-to-end encryption.
It’s plainly obvious that these protections are not the protections Proton VPN provides.
I think that VPNs are largely misunderstood tools, and that people should not grow accustomed to relying on them in situations where they aren’t suitable. VPN marketing already makes this far too confusing to consumers.
The difference between this situation and the hypothetical thread you proposed is that you would be saying PG actually is, which is not an evidence-based opinion, so to answer your question no it would not be allowed.
On the other hand, threads merely suggesting how PG could improve its trust and recommendations are frequently had here and are of course allowed.