It was always possible to have a standard midi file used on external channel strips. But the implementation was not very good. I think they were more intended for sending sysex then for playing back actual midi sequences, but anyway... I digress...
If they did something new and different then that....I can't find it either, not sure where it would be.
In order to be truly useful something like that would need to be global across the whole patch...not located in one single channel strip..so that it could send midi events to all channel strips of the patch. Ideally it would probably need to be something you add to the "Layout" of the patch..like a widget of somesort, that can play midi... kind of like a midi controller widget.. But anyway, I looked around for this the other day when I read your post, but I couldn't find anything.
OSX 10.15 (Catalina) on OpenCore - Logic Pro 10.6.1, VePro7, Mainstage3
5,1 MacPro 3.46ghz x 12 96gb ram