Any successor for Notifier service?

Hi there,
We will soon migrate from Juniper release to Koa in which the Notifier service has been removed. As the DEPR announcement pointed:

We hope to find a maintainable path for this feature, perhaps using the edX ACE infrastructure.

I’d like to know about the proper approach we should take, and whether there was any progress? then what challenges are there?
Also, it would be nice to know, what does currently do? Do you have completely stopped sending discussion forum daily digest messages?