Hi Marie!
Thanks again!
I can only speak for myself, but I believe the original underlying question needs to be answered yet. You said:
"We at MoodleHQ remain committed to supporting H5P as a core activity in Moodle and regularly prioritise work to ensure that new versions of H5P work in Moodle."
while a report of one of the 2022 MUA events states:
""To the question of whether Moodle has a roadmap for continued inclusion or development of H5P within Moodle Core, he answers: “No, not really, sadly no'' to the reason why, he explained [...]".
That's not necessarily contradictory, but to be frank, pointing towards tickets that have been open for quite a while without progress do not look too promising to me. For instance, the "save content state" feature is really not hard to do even without having documentation. All the required code can be inspected easily - and there's precedence. Lumi has included that feature in their node.js port of H5P, I have included it in one of my client's custom platform.
That's just a side issue though.
One should, in particular, not confuse the H5P OER Hub with the H5P Hub. The former is a pool of openly licensed contents on a central server. The latter is the visual interface in H5P's editor. The access to the former is using the latter.
While moodle may lack documentation of the API to access the H5P OER Hub, one can easily derive it from the code of H5P Hub client on github. It's essentially two endpoints that one can call, one to get a list of all available contents, one to retrieve a specific content. One essentially doesn't need to know, however, if one uses the H5P Hub. The WordPress plugin does, for instance, and I have ported the integration of the H5P OER Hub connection without any documentation in a couple of days in my free time just by checking the implementation in the H5P plugin for Drupal and moodle.
So, the real deal is the H5P Hub though, regardless of whether it features access to the H5P OER Hub or not. The H5P Hub is what moodle HQ decided not to port to moodle's custom H5P integration, even though there's basically nothing to port. It's a piece of Javascript that just needs to be included. Moodle HQ replaced it by a plain pulldown menu. I fully understand that there may have been organizational reasons to do so (some feature duplication, H5P branding, etc.), but that was moodle HQ's decision.
Now, the H5P Hub is going to become more important. For instance, while it currently is only used to select the main content to create, in the future it will also be used to include sub-content from within content types. That makes sense for H5P, because one can get rid of crowded toolbars in Course Presentation or Interactive Video, one can upload content to be used as sub-content, and so on). Such a dependance on the H5P Hub would essentially mean that later versions of H5P content types would not work anymore if the H5P Hub is not used. That's the future of moodle's custom H5P integration is if nothing changes. One could potentially come up with workarounds for that, don't know, because this is currently not implemented anywhere yet, but this is the hot topic. The future of H5P in moodle's custom H5P integration.
Having the H5P OER Hub is just a goodie that essentially came for free if the H5P Hub was supported. And having the H5P Hub is no big deal, because it's a separate module for a reason that just needs to be hooked up to a platform and then one doesn't need to worry about it anymore. That is what Lumi did, for instance, but moodle HQ decided not to do.
Sorry, I know this got a long post, but this is really something that users worry about. It's not weighing H5P Group's H5P plugin against moodle's custom H5P integration (I have publicly stated in some other post here that I think the latter is superior except for some missing things). It's about not knowing whether betting on moodle's custom H5P integration today will yield (severe) problems in the future. That's what lead some people to not use it (there's a post about this on this forums) but rather live with some disadvantages that the H5P plugin for moodle has. And, obviously, this is something that bothers Christophe, too.