If an obvious Mega-IP came along that was worthy of spending the third of the cost of a whole new park did come along - I don't believe any franchise fits that bill by ANY IP holder - it makes absolutely no financial sense at all to have a huge capital expenditure in one location. ROI would increase by spreading that IP across three parks. Even if Epic had opened in ~2009, it makes little sense to build all of Potter offerings in the one plot - their objective is to get more people visiting & staying for longer, not to thematically centre the same IP in one location - so i believe they would still do it the same way all over again to leverage attendance to across all their parks not just one.
If we escape the mindset that they are holding out for a singular IP to go into a giant 21 acre $2.2B land and it is not getting built whilst also considering it is more than likely Zelda goes in next door to Monsters in the next 2-5 years, then realistically one of those two remaining pads could literally come at any moment.
The reason i asked what IP would everyone choose from the WB library is if they do get a deal they might have to build sooner rather than later (contractually speaking) - and perhaps WB like the idea of their IP going next door to Potter