All you need to do is print the name of the certifying agency. If it’s reputable then it speaks for itself.
Many don't use agencies but they also don't use
fly by night, second tier "rabbonim", who all of a sudden have become professionals in the intricate details of catering a commercial pesach for for hundreds..
They use experienced and dedicated top tier rabbonim, who may not have public name recognition, so they want to explain that to you.
I did a quick Google image search and it seems that there are quite a few that write the hashgocha.

No hashgocha on this one, didn't check all the rest
Even among those who do mention some sort of kashrut oversight I don’t see separate swimming mentioned in any of the ads.
Umm maybe separate swimming is a given.
And gebrokts is a halachic concern.
Separate swimming should not be a given at a gebrokts program, where the crowd is often more MO. And should be inquired upon at all programs.
women's swimming should not be a given at any program at all. Many hotels don't have the setup for a possible mechitza
As an aside, if it does not say non gebrokts, it probably isn't.
its exactly what @dan said there's a huge variety of places and to draw conclusions of anyone place from another is silly and immature there are places that are prob serving treif and then there are places that may be more kosher than your kitchen
+1
And @aygart, I actually heard from a very Ehrliche program director that he is more comfortable eating from the hotel kitchen than he was at home the one year he stayed home. Odd, I know, but true.