The specification for Webmentions became a W3C recommendation three years ago, on January 12, 2017. The whole idea of a webmention, like its predecessors, is it is a way for one site to notify another that it is linking to it.
The receiving site gets to decide what to do with the notification…display it, store it, use it for stats…etc.
Now, in recent times, with additional Indieweb protocols being developed, webmentions are not getting the attention they once did in discussions. That is the sign of maturity. But there are still areas to explore.
On the development front, I have been slowly submitting improvements to the webmention plugin in WordPress. The webmention functionality in WordPress is bifurcated into two plugins, Semantic Linkbacks and Webmentions. They are being merged, piece by piece, each piece being improved and redesigned as it is merged.
The webmentions plugin now has the MF2 Parser, which it hasn’t since its early days. In future iterations, it will be hooked up and start parsing microformats, gradually moving this away from Semantic Linkbacks.