Multi-port USB chargers are fine. They have one AC plug and 4-6 USB outlets. Even at full draw, they're pulling a miniscule amount of current, like half an amp. Most ship circuits are rated for 15 amps.
The adapter that Crystal posted a link to is a little plastic multiple AC outlet. Those have been confiscated in the past. And many people have gotten them onboard the ship, but that doesn't mean they won't confiscate them if they find them. It just means the luggage checkers didn't notice them, or perhaps that particular checker was just less rigorous. It's also quite possible that the better-trained checkers will let simple multiple outlet plugs through, because they know enough to know they aren't technically on the banned list. Or it's possible they are on the banned list and the checkers are just not that good. No one at Disney will give a straight answer as to whether simple multi-outlet adapters are OK. In practice, though, they have been confiscated in the past, and people have not had much luck insisting that they're not an extension cord or surge protector. Thus I recommend against depending on them. If you bring one, have a plan for what to do if they take it.
The stateroom hosts will never confiscate stuff; I don't think it's their job, but even if they're supposed to, it would kill their tips. It's the luggage checkers who confiscate stuff.
I agree with you that technically it is not a surge protector or extension cord. I'm just telling you, for reference, that Disney (and other cruise lines) often confiscate anything with multiple AC outlets, even if it isn't a surge protector or an extension cord. We have had many, many examples of it being reported here and on other boards. I think it's a training issue; it's hard to show the staff every possible multi-outlet adapter and say, "these are fine, but these should be pulled out" so they just confiscate any multiple outlet adapter, period.
