Hello! I'm an admin at some Albanian wikiprojects and I very much liked the changes that are being discussed about talk pages. I've been dealing for quite some times with new users and the way they interact with the software, hoping to make it easier for them so I can give some opinions on the subject.
For starters I can say that social media logic is dominating online conversations these days and whatever's true for Facebook, is considered a given for every kind of conversing online platform. They tend to expect to be able to mention/call someone by using the @ symbol and their name. Gone are the days when it would be more logical to use the word ping - a forum kind of style of mentioning. Maybe Ping is more well-known in the English world but @ is becoming more universal as time passes and more and more platforms starts to have the same style of mentioning other users. Mentions failing to send, problems with multiple-mentions, problems with editing or removing the mentions are all alien technical concepts to new users. Adding on that, signing their answer is something no new user does, no matter how much they get bombarded by intro-information and disclaimers that advise on doing just that. The word "sign" just doesn't make sense to them until they are advised personally by someone during the conversation. They expect to have their name and date automatically added after their "comment" (using social media terminology) and are usually very appalled by the crude interface Wikipedia has in these things. The same thing with indentation. Usually, the point when we have to explain indentation to them, it's usually the point when they start to express their frustration on the site's interface. "All these technicalities only to write a comment. Imagine writing an article!" In the Albanian Wikipedia, I've made the mentioning template as following "{{@|Username}}" only to suffice to that kind of logic. I've thought of proposing to activate "Flow" too to deal with the indentation and we've been thinking of having a sign bot. It would be very nice if we could have a single solution to all these problems.
Another problem that is very present in small wikis is the lack of discussion in general. You mention here that new users are confused by the terminology (add a new subject) or the purpose of the talk page in general, confusing it with a forum page. That's true but in small wikis we have a bigger problem: Not many users (new or veterans) actually use the talk pages at all. Since talk pages need to be created first, if you are not sure of their purpose, given that they somehow create the impression that they're a technical thing (since it's not a mainspace page), not many users dare create them. And even if the page is already created, they don't know exactly what that page is for. It may seem like a common thing to know in big wikis, but in small ones, the situation is a bit different. The few ones who actually have dared create one and proposed changes on it regarding the accompanying article, have spent hours, days and months without any answer and went on to do the changes themselves anyway and never used a talk page again. The whole talk page infrastructure works well in big wikis because they rarely have articles without their accompanying talk pages, all the talkpages have a well created header that explains what's it for and how to use it and they have bots dealing with their archiving process (and MANY veteran users already creating the right path/example for new ones). In small wikis, talk pages are usually only redlinks and on the few occasions that they exist, they are literally only blank pages that no one looks after since they don't create notifications, except for in the watchlist, again an option not many new user/veteran users use in small wikis. It would be nice if that infrastructure could be automatically applied by default to all talkpages as needed, without the use of manual templates and bots. Starting by the name of the talk page that makes it more clear what that page is for (discussing for changes in the article), continuing with a clear explanation on how to use it (the explaining header) and maybe a more eye-catching position related to the accompanying article (not many new users instinctively see at the top side of the article for somewhere to discuss about it), and maybe even dealing with the archiving process without the use of any user bots. Talk page autocreation (and even the ability to delete them together with the article if so needed - a phab request for quite some years now) would be a good idea too to implement.