This misses the point completely, of course. The issue isn’t just (or primarily) how long WDW takes to build something after groundbreaking, it’s the fact that they make much-hyped announcements and then drag their feet for months or years, using the announcement alone as a way to avoid making OTHER announcements. So Disney and it’s fans have been able to answer charges that the parks are stagnant by pointing to Tron for at least six years - considerably longer if we consider the period after opening in which it will be considered “new.”
Compare to Universal, where impressive additions like Bourne just seem to happen. This is one of the issues with the Moana area - if it were simply a nice addition that appeared, similar to Unis Speingfield expansion, it would be much more well received. As it is, it is a major part of a sweeping and very visible makeover of a deeply flawed park that has been hyped for years. On those terms, it’s almost guaranteed to be a failure.