Per what @ovasileva and @Esanders and I talked about offline in separate conversations, the next steps here are:

• 1) The Editing Team to decide what they think is the best approach for "telling" the ToC when and how it needs to be updated upon an edit being published. E.g. Do they support the approach being proposed in this ticket? Do they propose an alternative approach?
• 2A) If the Editing Team supports the approach currently being proposed in this ticket, we'll provide an estimate for when the Web Team can expect us to have implemented said approach.
• 2B) If the Editing Team supports an approach that is different from the approach currently being proposed in this ticket, we'll communicate as much to the Web Team so that we can work together on defining a path forward to ensuring the ToC has what it needs to update itself after an edit is published.

In T307480#7910919, @ppelberg wrote:

Per what @ovasileva and @Esanders and I talked about offline in separate conversations, the next steps here are:

• 1) The Editing Team to decide what they think is the best approach for "telling" the ToC when and how it needs to be updated upon an edit being published. E.g. Do they support the approach being proposed in this ticket? Do they propose an alternative approach?

Per the meetings the Editing and Web Teams had last week, specifically the inter-team meeting we had on 10 May, the Editing Team supports the approach being proposed in this ticket's description.

• 2A) If the Editing Team supports the approach currently being proposed in this ticket, we'll provide an estimate for when the Web Team can expect us to have implemented said approach.

In-line with the above, the Editing Team is going to write a patch to implement what the task description describes and the Web Team will review it once done.

Change 802680 had a related patch set uploaded (by Bartosz Dziewoński; author: Bartosz Dziewoński):

[mediawiki/extensions/VisualEditor@master] Fire new 'wikipage.tableOfContents' hook to update TOC after save

https://gerrit.wikimedia.org/r/802680

Change 802680 merged by jenkins-bot:

[mediawiki/extensions/VisualEditor@master] Fire new 'wikipage.tableOfContents' hook to update TOC after save

https://gerrit.wikimedia.org/r/802680