My own understanding of our acceptance of ABP style blocklists is so that list maintainers can provide their intended-for-dns-blocker lists in a different format other thna HOST format.
This is a pretty common practice recently - lots of the mega-list curators switched to this format to, in theory, cut down their list sizes while still providing the same blocking effectiveness.
It is not expected, for example, to take a list that is an intended-for-browser-blocker list, and throw it into Pi-hole. Of course there will be false positives in this case.
The intent is to support a very specific subset of ABPs syntax.
Paging @WaLLy3K and @lightswitch05 for their thoughts on this thread as blocklist maintainers/curators, if they have any!
I don't see why not, but in all honesty it is probably not me that will be writing the code for this if it happens, so I wouldn't like to make any promises on anything