Though WP deprecated the Links Manager, it's still in core, and as we all know, they're BIG (maybe too big) on backwards compatibility. I suspect that if they did remove it altogether, they would abstract it out to a standalone plugin. There are also newer updated plugins like https://wordpress.org/plugins/simple-links/ for those who are more concerned. Either way, I'm hoping that this sort of functionality "comes back to life" on the open web, so perhaps WP will not only bring it back, but put more resources into extending it.