I was so disappointed with the complete mess the current abc2ly makes of Irish tunes from the vast repository at thesession.org
that I started looking into this. The others mentioned that using abc2xml and then using musixxml2ly supplied with lilypond is the way forward. I found this to be logical, from the programming point of view of using a single intermediary interface (MusicXML), and it works great, except for messed up header blocks, which I just delete and hand edit.
It's such a good solution that I have decided to attack the musicxml2ly problem by finally getting around to doing the lilypond wholesale uplift of the ancient python version, which would offer many benefits in many areas. A big project, but I am starting on it.
So I don't think it matters at all if the current abc2ly goes away. There's a good current solution presently.
I do actually use it on occasion.