User value and company revenue, in general, form a [pareto frontier](https://en.m.wikipedia.org/wiki/Pareto_front). The company can pick an "angle" (trade off some user value for more profits and vice-versa) but both extremes are bad in the long term. They need to strike a balance.
A company that continuously invests their efforts on maximum revenue subtraction eventually pushes their users out. Similarly, a company that invests too much into research and present user satisfaction, particularly when users don't pay for the product, is set to have some financial and economical problems in the future.
I think this is borderline ethical. For sure it's over 9000 in the Maquiavellian scale (I mean the gymnastics behind "please don't say that this is us pushing for worse results, that's a very negative message" are genius and I can see that working really well under certain circumstances in a corporate setup), but that doesn't mean that it's unethical _necessarily_.
I have been using GrapheneOS for a couple of years and I feel frustration about this announcement. At the same time, sounds like not much of a biggie, but I'd prefer the burden of updating the apps not to be on the GrapheneOS contributors.
On the other hand, I can see Google's arguments and "plausible deniability" that this is not Embrace, Extend, Extinguish: really nobody expects them to "Don't be Evil" anymore, security vulnerabilities in these apps are probably the last thing in their priorities, and the target audience for these apps is really small.