Youd be amazed with how much FF XIV is growing/has grown and how much WoW is shrinking/has shrunk, and Blizzard has always released some sort of major patch near to other MMOs major expacs or when new MMOs are released, they always say it isn't intentional but it definetly is.
And the pacing they are releasing patches has absolutly nothing to do with their capacity to properly space out raid tiers, we haven't seen how this will pan out in the long run, all we have is Blizzard telling us they learned form their mistakes. If Nighthold lasts only 4 or so months then they clearly haven't learned anything or they are absolutely sure they can come up with the xpac super quickly this time around. The whole point of spacing the tiers is that its nonsensical to end a tier in 4 months only to have your last tier last over a year. 4/4/12 is dumb when you couldve had 6/6/8 or something like that. Blizzard did buy sometime by making EN a pseudo tier but if they cut NH short the same problem will arise when we reach the last tier.
As an example if we take the time beteween Pandaria and WoD launch (not using WoD to Legion cause WoD was a shortes xpac, Blizz already stated Legion will be as big as Cata/LK/Mists/BC) we have roughtly 26 months. If we asume they will take more or less the same time to come up with a new xpac (they have always taken a similar amount of time to develop xpacs) lets say they'll take 24 months this time. So we had EN lasting 4 months, we will get NH for another 5, then lets say we get Tomb for 5 and then that leaves us with 10 freaking months of last tier. Thats not spacing the raids, at all, that is throwing a pseudo tier on the start and then hopping to God you develop the next xpac fast.