the relevant sentiment is:  thanks for whitelisting a fixed number of them so i can block them.

Not quite... Vixie wants the services to not exist to any (possibly compromised) device on his network.  So it's less about what Chrome does than whether the service shares fate with a service he wants to use.  Google supporting DoH on 8.8.8.8:443 is acceptable to him because he can block that, while Google supporting DoH on www.google.com/dns would not be ok since he would be unable to block it.