Sort of—WotC tweeted out that the "planeswalker" cards in this set aren't MTG planeswalkers; in other words, in this set the term doesn't mean what it usually means in MTG lore (though the card functions the same way mechanically).I don't know if it got mentioned yet, but Lolth was revealed as a Planeswalker. (so THAT'S why she went Silent.......okay not really but I could still use that for my Drow Schism 5E lore for non evil drow.)
Of course, Lolth can be a MTG planeswalker in your campaigns if you want her to be.