I'd absolutely love this, as I've said in other threads.
I feel like this is a pack the game devs would love to make, just based on things they've tweeted and objects in the game, but they don't think enough of the community wants it. That may be the case, but modern/realism simmers have had a lot now, I feel like it's time for those of us who like fantasy and historical (the two often seem to go hand in hand) gameplay to get a pack like this. Perhaps the medieval world could be a destination world that can be accessed through a time portal of sorts. I'd like if they brought in elves, fairies or witches with this pack, too.
I LOVE Sims Medieval, and would love to see a lot of things from that brought in to Sims 4.