Thanks to the tech team and everyone else who helped this feature become enabled.
I also hope we can have this featured enabled by default for old and new users soon, even on the big wikis. Doing that will bring many experienced editors back to the wiki.
As someone with tens of thousands of pages on my watchlists, I think it would be reasonable to disable this feature on enwp for people with more than 5,000 content pages on their watchlist, as the content pages change often on enwp. However that approach shouldnt be applied to all wikis indescriminately; e.g. wikisource content pages rarely change after the initial burst of editing.
-- John Vandenberg