We don't even know for sure how Fastpass + will work for guests staying at WDW run resorts.
You'll take a guess. SoG seems to be more like DTD hotels. They don't use WDW transportation. There was a time in which they weren't going to participate with EMH--they didn't want to pay what Disney wanted to charge. I'll guess SoG won't have much to do with Fp+.
S/D. No idea. They participate with EMH and use Disney transportation. I'll speculate there may be something in their contract (lease) with WDW which guarantees their guests certain perks which are offered to WDW resort guests. I wouldn't be surprised either way.
edited to add: I posted before Cheshire Figment. Based on his information I'd say the chances are very small S/D will participate with FP+