I didn't see a correct answer to this.
There have never been owlfolk in an MTG setting. There are many owls, but they're just Birds. I'm pretty sure art has depicted owl-headed sphinxes and gryphons, too, but they're still sphinxes and gryphons.
There has been one rabbitfolk.
Kwain, Itinerant Meddler is clearly a rabbit. However, the set he is in, Commander Legends, is not associated with any one setting. Instead, it specifically includes characters from any of the known settings in MTG's history. So, yeah, they exist, but it hasn't been made clear from
where. The flavor text suggests the inspiration may have been any of the numerous rabbit fables or Alice in Wonderland, so it may very well have been a card that was designed for Throne of Eldraine and was left out for space (this is pretty common). The other rabbit creatures have been various rabbit-beasts like jackalopes.
I do not recall MTG faeries ever being presented as anything other than the diminutive creatures that D&D generally calls pixies or sprites, either. Throne of Eldraine, mentioned by a number of other posters, does have a fairy tale theme and lots of faeries (it's one of the more common creature types) but they're not unusually large, AFAIK.
There may have been fairy-adjacent goblins. MTG is kind of known for inventing oddball origins for goblins, and there are
always goblins. It's almost played like the MTG equivalent of the carcinisation phenomenon. I remember the planeswalking characters point out that it was strange when they travelled to a world which
hadn't evolved goblins. The only actual hobgoblins were on Shadowmoor/Eventide, IIRC, but I don't recall their origin.
I'd wager they're just going to have an adventure path in the Feywild or Shadowfell. They're some of the more interesting locations in the game, and some of the best lore to come out of 4e. I'm surprised it's taken this long to get to.