Ruin Explorer
Legend
I suspect not, or if they were, there was some kind of divergence, because the tone and style of the D&D version are drastically at odds with the MtG version. The MtG version of Strixhaven is considerably edgier and far less "cozy fantasy" than the D&D take, and it's just a really different and much scarier and more "YA novel"-ish vibe.I'm pretty sure was designed for both MtG and D&D at the same time.
Re: classics, I think to be a classic you have to probably be fondly remembered in later editions, or better yet, have people want to update an adventure to a more recent edition, and the only 5E adventure I definitely see that happening with is Strahd. It will be interesting to see if it happens with Wild and some of the others, but I suppose we won't know until 6E is out.