It’s still there 
↓
But, yes, I haven’t taken a look at it recently. Could be totally broken. I know there’s a few bug reports floating around I haven’t had time to get to yet. When I do find that time, I’ll finally actually publish the plugin in plugin.
I know asking if a feature would be welcome in core because I don’t really have time to maintain it as a plugin is cheating, but @team would a “post from rss feed” feature be welcome in core? It seems to be a reasonably frequent request and is a feature in other forum software.