If a product forces you to opt-out from telemetry, it makes sense that extensions would approach the problem the same way and force you to opt-out from each extension's telemetry.
I'm not saying that's good, just that it makes sense that whatever ecosystem/community spawns from your product, they adopt the same methodology as the main product uses.
It makes more sense that the extension would check the configured telemetry enablement state and use that. Perhaps provide an extension-specific override, but certainly don’t default to anything besides the global value.
This is what happens if you use the first party telemetry module msft provides, but obviously not if you’re just sending random http requests.
I'm not saying that's good, just that it makes sense that whatever ecosystem/community spawns from your product, they adopt the same methodology as the main product uses.