It's true that this and Colossus will be similar, in that they are coasters which will have 'standard' trains and a 'standard' lift hill (assuming, of course, there's no surprises like spinning cars or whatever)
I wouldn't be surprised if this is being geared up mid-to-long term as a "like-for-like" Colossus replacement. When Old Town and the island behind Swarm are eventually taken up, you're not left with much room for expansion, so do have to consider removals and replacements, and Colossus would be the first choice in terms of major coasters.
Project Exodus would be a similarly iconic coaster for the park, and similar in terms of maintenance. (If anything, probably easier to maintain, given the problems the park have had with Colossus' supports around the lake)
At the same time, it's not hard to imagine Colossus staying for a good while yet. It is *the* coaster which put Thorpe 'on the map'. It's still pretty popular. And who knows, with a retrack, it may become smoother (and be a cheaper alternative than completely ripping it out and building something new).
So yeah, it's very 50/50 - I genuinely would not be surprised either way if we see it here or not by the end of the decade.