That's fine, if it is opt-in and clearly spelled out. Some of us do confidential work and leaking URLs visited and field contents to parties not subject to NDA is absolutely not acceptable in any context.
Yeah, a coherent privacy model, disclosure etc are all super important. It's just irritating to see people act like software of this type can rationally be shipped without any telemetry to a big group of users who aren't compiling it from source.
Naturally a ton of work has to go into properly designing telemetry for something like Firefox or Chrome - not only is disclosing URLs a no-go, but you need to make sure your telemetry isn't unintentionally exposing details that are identifying in some other fashion, like on-stack data from a crash report or that sort of thing.
