Eh, I wouldn’t say that plugins are less likely to change than plain old Discourse. In fact I was mostly letting you know it was a plugin so you could @ the developer of the plugin (who happens to also be a developer of Discourse) directly.
I’m not saying it definitely will change (especially because I like the reply-to-yourself option better myself), but I wouldn’t completely dismiss the idea of a plugin changing either. Some of them are under pretty active development.