*{{draft}} {{random person's idea}}* !!!
Executive summary: add Flow discussions to pages with {{#useFlow:1}}.
Converting a Talk page to a Flow board is disruptive and controversial. It delivers better conversations (for new and average users) right now, but it will be years before Flow nails all the other use cases for talk pages (collaboration, metadata, workflows). Our workaround for that period is to put stuff other than conversations in the Flow board header (nomenclature https://www.mediawiki.org/wiki/Flow/Nomenclature#Picture). Flow topics live in an external cross-wiki DB separate from the page, but I haven't seen a good use case why we need the Flow board header to be in this cross-wiki DB.
Maybe it doesn't have to be so black and white. Imagine a world where Flow topics appear on a talk page but it's still a wikitext talk page. Enabling Flow on a page would be like LQT – someone adds a {{#useFlow:1}} magic word to a page and it gets Flow discussions. We de-emphasize the Flow board header, because you still have an entire regular page for templates, categories, workflows and whatever.
*+ No disruptive conversion*
*+ No bugs with categories in Flow board header*
*+ Avoid issues with changing the content model of a page*
*+ No complaints about narrow Flow board header*
*+ No break in the page history*
*+ No need to for a tricky archive-existing script* Although admins might choose to run a bot to move old wikitext section topics to an archive when adding {{#useFlow:1}}. *+ Don't have to solve the other three talk page use cases* (collaboration, metadata, workflows) *to gain Flow's improved conversations*. *+ The Collaboration team is adding an optional feature to existing talk pages* *, rather than perception of usurpation and war*
*+ We get feature parity "for free"* A number of complaints about Flow boards shift, because part of the talk page remains wikitext that users can view-source, diff, revert, monitor, etc. in the usual way. Topics are still a very different animal. Bots don't break, they will add stuff to the wikitext. Special:Search can still find text in the page (but not in its Flow topics until we do the search integration we need to do regardless of this proposal). Page move, #REDIRECT, etc. all kind-of work.
*+ We gain flexibility* A pure discussion page like Talk:Beta Features/Hovercards https://www.mediawiki.org/wiki/Talk:Beta_Features/Hovercards can still be {{#useFlow:1}} and a minimal wikitext part. LiquidThreads did it this way and AFAIK the flexibility was useful and non-controversial. We could support different behavior, e.g. {{#useFlow:*42*}} might only display a link to Flow topics. See "Feeds" section below.
There are downsides.
*- Two ways to discuss on a talk page* If {{#useFlow:1}} then we would adjust the [Add topic] tab to jump to the *Start a new topic* Flow form. Still, old-timers would continue to create wikitext section topics.
*- Hybrid page user experience is messy*
*- Hybrid page implementation is messy and slow* MediaWiki has to load regular wikitext then load Flow topics, handle two kinds of JavaScript, etc.
*- The page gets infinite scroll behavior* (People keep demanding the notion of archives, if we respond to them and provide a way to move old and closed Flow topics, e.g. to a /All_topics_archive subpage, then a talk page with Flow topics could adopt an approach where it *doesn't* scroll forever. That is orthogonal to this proposal.)
*- The upcoming Flow TOC and fixed header has to coexist with regular page TOC* If Flow discussions are the last thing on the page then once you scroll down to them you're in a different kind of thing, so it's OK to get a different appearance. Like LQT. The {{#useFlow:1}} could automatically add a "Discussion topics" to the end of the regular wikitext TOC. Displaying all the Flow topic titles in the regular TOC is very hard, and impossible if there are hundreds of them, but maybe the TOC could display the first (newest) 20 topic titles.
*- Need to go two places to see full history of talk page* The talk page history (probably) wouldn't show all changes to the "Topics on the page", you'll still have to go to a separate board history.
*+/- "Flow board" goes away* We're already de-emphasizing actions on a Flow board. You watch individual topics, you get notified about them. "Flow board" evolves into the notion of "All the topics started on this page". *+/- People might add* {{#useFlow:1}}* to regular pages* On the rest of the web, you scroll down a page and arrive at discussions about it. There's value in splitting off discussion of an encyclopedia article from the article itself, but maybe WikiProject:Breakfast or even User:SPage doesn't need the confusion of a separate talk page.
*What about Feeds?* This ties into the "Feeds https://www.mediawiki.org/wiki/Flow/Basic_information#Feeds" feature, for which IMO we need a more concrete plan. As I understand it, the main reason for the pain (UUIDs, storagemodels, separate revision management) of a separate cross-wiki Flow DB is so that a conversation about an image in an article can appear on the article's talk page, also on the image's talk page on Commons, on the image author's talk page on Commons, and in the subscriptions of people interested in the article or image. This is fantastic, but in order to work when one of those talk pages isn't a Flow board we have to wrestle with all the issues of a hybrid page (TOC, infinite scroll, etc.), so why not do it now? I don't know how a Feed would be enabled on a regular talk page, but it sounds like an elaboration of this, {{#useFlow:|relatedTopicFeed}}.
Thanks so much for reading!
-- =S Page Collaboration team engineer