The page model was originally switched to Flow because the admins kept getting so many requests for "one-off" changes to new pages. It proved to be less work to change the default and freely grant one-off changes back to wikitext (ask any admin you know, or start a thread here whenever you want; if the page doesn't already exist, it's not considered a big deal, and Flow-to-wikitext conversions are possible).
Editing's planning an A/B test for Talk pages project/Notifications. It will hopefully emerge from instrumentation purgatory at the end of this month, run for about a month, and spend another month while the analyst figures out what happened. Depending on the results, the Editing team will make a recommendation. My guess (but data rules) is that they'll suggest enabling automatic subscriptions for newbies and manual subscriptions for old hands. My second guess is automatic for everyone, but with a highly visible opt-out button, which would have to be built. (Also, by this point, it'll be August, which means Wikimania, and nothing else will happen for weeks.)
On the assumption that the local community would first want to have this information plus (assuming the results are favorable) have the [subscribe] button deployed, I think the very earliest that people would want to talk about any changes would be September (October or even November being more realistic, since everything takes longer than it should).
As for the Editing team's role: They'll provide information and recommendations to all WMF wikis, but they weren't consulted on the switch to Flow in the past, and I don't think they expect to be consulted on any switch away from Flow in the future.