This will automatically happen because the hook is directly tied to HookUtils::isFeatureEnabledForOutput( $output ) -- so any page that has DiscussionTools enabled will inherently have the MobileFrontend talk overlay disabled.

Unless there exists some case where DT wouldn't be enabled but we want to disable the overlay anyway, I think this ticket is redundant.

Yep, that work happened in T280051.

@ppelberg I still see it on enwiki. I don’t think it’s resolved yet.

We are down to enwiki as literally the only place that it's enabled, mind you. :D

I know it’s only one wiki, but that’s still one more than what I’d expect before calling this done.

We'll change the config on enwiki soon as well. There's a separate task for it: T328942: [Config Change] Enable all DiscussionTools as default-on features at Phase 2 wikis (mobile)

In T298066#8627586, @Tacsipacsi wrote:

@ppelberg I still see it on enwiki. I don’t think it’s resolved yet.

I'll re-open this task and mark us closing this as being blocked on T328942 (the ticket @matmarex linked above).

By way of the patches to resolve T328942 being deployed, in effect, the MobileFrontend overlay has been removed at all Wikimedia Foundation wikis.

Work to remove the corresponding code will happen in T319145.