HEA was supposed to be a temporary show until the 50th Show which was supposed to be Enchantment. The 50th Show seemed to vacillate between supposingly sticking around 'permanenlty' (as permanent as any WDW show) or, only being temporary.
Then it was discovered that guests liked HEA more than Enchantment, and also, guests were very disappointed that the 50th anniversary show did very little to highlight the history of WDW, and it premiered pretty late missing the 50th. And so, they decided to go back to HEA and declare, most definitely, that Enchantment was always meant to be temporary.
On top of that, HEA was created by a third party company in conjunction with actual Disney animators. Then WDW saw what they did and thought, "We don't need to pay an outside contractor. We saw what they did, and we can do that and save some money."
And then proceeded to offer an inferior show in place of HEA.