I know a few people were asking about this, and it's now confirmed that Skyrim Special Edition will be getting its own strategy guidebook.
https://www.primagames.com/games/elder-scrolls-v-skyrim/official-strategy/return-skyrim-hd-special-edition-walkthrough-strategy-guide
I haven't seen the original guide, so I'm not sure how much has changed or been added. But I assume all the DLC stuff will be new.
(sorry if this is old news)