It may depend on the manufacturer but my slide did not depend on the dinette for any structural strength. I removed mine with no issues. You may or may not want to permanently seal the outside storage access doors, if any, for the space under the dinette. I guess you have already made sure nothing like your inverter, or water pump, etc. is located under the dinette.
I had two outside doors that accessed that space and I permanently sealed them up. I also rerouted the power cord for the slide lights and sockets. It ran under the dinette and just needed to be secured to the wall.