I drew a sorta pony-shaped vagina on the Spitfire I did a couple of weeks ago, but I don’t really like how that looked compared to a human-shaped one. So I give them human like bits for the current series, because I really like how they look like.
Also looking at references for the one pony-shaped vagina I did was a bit awkward, to be honest.
If I feel like it I may do one or two pony-versions after I’m done with the mane six, though, but don’t get your hopes up, sorry!