I think if they tried to close down The River Adventure, it would really bring down the whole JP Land for the time being, but NOW with a brand spankin' new Jurassic World themed Velocicoaster, it'll bring a ton of attention to the area, so if they wanted, they could close down River Adventure to remodel to JW. My theory anyways.
Since Jurassic World isn't coming to Epic Universe, they may just go ahead and rebrand IoA as well like Hollywood did.
Honestly I wouldn't mind, because the Jurassic Park theme is aging at IoA. And they aren't even trying to improve or remodel it, that's why the River Adventure is looking bad. If there was a choice to keep it as is, or get brand new state of the art refurbished design, I'd take that.
Jurassic World is fantastic, I loved the movies and the theme park look and all. The movies may have had a few plot holes, but you gotta admit they knocked it out of the park in terms of how the park looked and operated. I'd go there in real life if it existed!
(Plus if they largely removed the main three domes on the Discovery Center to remodel into looking like the Towering Samsung Innovation Center, I'd absolutely love it.)