In episode 34 of the Dice, Camera, Action! D&D stream, the legendary elf Drizzt makes an appearance. Is this a custom plotline that Chris Perkins added, or is the drow really one of the NPCs that players can interact with in the hardcover campaign?
Drizzt does not appear in the campaign, but one of his companions (Harshnag, page 118-120) does appear as an allied NPC. And there's nothing stopping a DM that wants to add the legendary dark elf ranger to the campaign - besides a lack of official stats in Storm King's Thunder.
Drizzt is not in Storm King's Thunder. An electronic search returns no hits for his name within SKT, and a manual inspection of Appendix D: Special NPCs does not find any reference to him.