The gluten free offerings won't be sitting out. You'll have to ask each and every time you want the gluten free goodies.
That being said, from the reviews I've read, each resort seems to have different levels of gluten free offerings. I've only tried CL at the Polynesian resort and I have nothing but amazing things to say about them. The chefs actually gave me enough stuff to bring to my room for me and my kids so that we didn't have to keep asking over and over for things up in the lounge and when they'd see me they'd see me they'd make a point of checking to see if we were well stocked or needed more stuff. They really did take great care of us. I should also mention that we're free of a heck of a lot more stuff than just gluten and they did an amazing job of taking care of us.
IPO had me pretty freaked out before our first CL stay. When I asked IPO about what would be available, they sent me a link to Garden Grocer and told me that I'd be better off ordering my own food as they couldn't guarantee our safety in the lounge. The chefs AT the resort on the other hand were unbelievably helpful. They prepared safe versions of the evening food for us (for instance on sushi night she made safe stuff for us including a set of rolls without any of our allergens plus tuna poke using San-J gluten free tamari). There arrangements made for us to have safe breakfasts as well.
I did always notify Special Diets about our CL stay and asked them to notify the CL chefs but of our 3 CL stays, they've only been notified ahead of time once. When they weren't notified, they didn't have as many options available for us when we arrived but by the end of the day they loaded us up.
What resort will you be staying at? Maybe people with experience at the particular resort where you'll be staying can chime in with feedback about that resort.