The main pool area at HGVC is near the little lake and yes, there have several reports of a couple of small gators showing up in the lake, as there have been, in *ALL* of the lakes on Disney property and many other bodies of water in FL. Disney even has a crew that traps gators in undesirable, tourist locations, marks them with red paint markings and moves them to the preserve land/swamp areas. If they repeatedly return to areas near people, demonstrating less shyness with humans, they are moved to a place that will accept them (like Gatorland park or the zoo). This was told to me by one CM from Fort Wilderness Campground and another CM who works the boats on Crescent Lake (Epcot area resorts).
Anyway, the set-up of the main pool area at HGVC is such that it's separated by a substantial fence/wall. I wouldn't give it a moment of worry, to take a nice poolside nap there, assuming I had no small children in my charge by the pool (water safety).
BTW, we learned quite a bit of reassuring info about freshwater alligators found in FL at the Orlando Science Center a while back. They have baby gators there and the naturalists can share a lot of handy info. These gators are not at all interested in humans as a food source. The only humans that would even fit into their bodies would have to be quite small (young toddler) and hopefully, those are NEVER out of your sight/grasp outdoors anyway.
Unlike aggressive saltwater
crocs, gators will generally only bite at humans when they perceive a threat. They are sluggish when it's cool and sluggish when it's hot, mostly doing their food hunting (rabbits, etc.) when it's warm out (~70ú-85ú out) and having seasons of very little activity. They can go a pretty good length of time between meals too. Hope that helps.
