Does the lack of reforge in WoD mean that you're gonna be encouraged to change specs between bosses less often?
Assuming you got 2 dps specs: if spec A state priority is haste, and spec B state priority is critical chance, then if the gear you currently have has much more haste than crit, you'll significantly perform better in Spec A, even though Spec B would be better in some bosses.
If the specs aren't too far apart in terms of numbers, then due your itemization (like gear being around 1 stat), then they won't differ much in terms of results in bosses, which would make the player opt for the same spec the entire raid, right?
PS: or it could also mean people will keep needing gear during the whole patch just to be able to min-max each dps spec (like hybrids used to do for different roles). Thankfully you don't compete for individual loot in flex/lfr I guess, otherwise it would be chaos lol.