Xtreix
I can totally understand that the project wants GrapheneOS be presented as a strong, vital OS. Frankly, I am convinced that it actually is.
Nonetheless ...
1.) If that age verification was actually implemented and related developers indeed relied on Google Play Service API with that utterly questionable, barely-security-related and anti-competitive certification-by-contract scheme - maybe because of app developers just being lazy, taking a "well known" (google promoted) functionality and/or not knowing of better hardware attestation - then I'd say that Forbes actually had a point, there.
We see the annoying examples of certain apps following this regrettable pattern discussed in other threads.
I'd personally see some risk in the other points as well:
2.) If (note: another if) Google continued on flitting about moving more development closed-source - and in the worst case: attempted to shift as much resources into a private OS, leaving AOSP only to a sort of skeleton development - it would be a bad course, IMHO.
Sure, I'd expect that such a move would backfire badly on the long run, since they would disturb and weaken the whole ecosystem whose (relative) openness allowed it to become such gigantic success story over the last 15 years. I find it hard to imagine how splitting this and weakening the formerly shared AOSP development would be without impact to all Android-derivates incl. GOS.
I hope they will be smarter than that, but as I already wrote, some weeks ago: Bad business decisions by certain management levels have been made before.
Again, for everyone just skimming posts: We are in the realm of speculation here.
And concerning
3.) The pseudo-Crime-Anti-PR and mischaracterisation of some, apparently misguided LE bueros + media outlets (and their text generators?) doing a really bad job ... IMHO that can have an adverse effect, too, if such misconceptions are not countered by solid PR and quality journalism. If the misconceptions solidify in the heads of the wrong decision makers, that could lead to bad publicity and, even worse, influence regulatory decisions and thus pose a political risk.
I definitely can anticipate better or worse potential developments for these aspects. I don't consider the article completely pointless. Now, are potential, worse-case scenarios enough to be considered an actual threat? ... I don't know - you decide.