I'm a former PhotoPass Photographer. I'm honestly not sure, but I would skew towards "no."
There was a fairly big list of things we couldn't take pictures of, most of which was other corporate logos. For example, at Animal Kingdom we couldn't take pictures in front of the Rainforest Cafe sign. We also weren't able to take pictures that made it look like our photos were advertising other companies services. For example, I remember there was a trend (and it might still be around) of a multi-level marketing/pyramid scheme company called World Ventures that gave their people these blue signs that said something like "You Should Be Here" or something that basically insinuated if you used their services than you could get a free trip to Disney or something pretty scammy. We also couldn't take pictures of people holding newspapers. That was a weird one. I think people did it to show their friends back in their hometown how far they traveled or something, but Disney was concerned that we were taking pictures of some terrible headline. We also couldn't let people hold newspaper headlines next to the characters because it would look like they are promoting a news story, especially if it was something controversial (I think?).
Idk, the rules were kind of complicated but luckily things like this didn't come up too much. I say take the sign and just ask. I'm not sure if photographers are allowed to use guests cameras at this time, but in the past we usually had no issue using them.
