The wording on that sign isn't the best, but I can definitely believe it's something that someone in lower management printed out on their computer and posted in a break area without any real authorization. That happens all the time in a lot of different areas. Even if it was official information, it certainly wouldn't be the only 'white lie' the company asks CMs to tell.
Also, call me a sheep or whatever but
I don't see the issue with trying to prevent guests who know literally nothing about alligators from panicking over them. The other day I had to explain to some freaked out lady that no, the little lizards that live all over the place are not baby alligators and can't hurt anything besides small insects.