Be realistic, building a new park costs a ton of money. There is grading the land, infrastructure, designing the park, building it, parking, a hotel or 2. So, realistically (and as mentioned before), this park won't be 100% filled and finished when it opens (like every theme park in the world). I'm sure what is being build will be amazing and give you enough for a decently filled day when it's crowded. The amount you get out of it difference on how deep you want to dive in the experience but I think it will be 60% (at best) when comparing it to USF or IOA.
So over the years Universal likely will fill in the empty lots, tweak their rides and add and replace rides at USF and IOA. All this to keep guests coming back to all parks.
Taking all this in account it's ignorant to even think about yet another park. Will it one day be there, probably, will I still be alive when it opens? Probably not.