I didn't think about the pool at first, but based on the position, you're right. It has big shoes to fill. The pool would need to either a) be something completely different or b) go back on the nostalgia of River Country in order to not anger people. Looking at the atmosphere they're going for, B seems like the more likely option.
I personally never had a chance to go to River Country, but I heard good things. Hope this does something special.