I saw this screenshot on the first page which shows a pretty good comparison between a Kul'tiran male and a regular playable human:
I feel that the Kul'tiran, even for something that should be a "larger human", is disproportionately big. I could see him being a head or two taller than a regular man (Stormwindian heads), but at that size he's closer to a Vrykul than a Human. He's more or less as tall as player models allow, as tall as a Tauren. This gives the impression Kul'tirans are an entirely new race, not just a nation of humans, which is particularly weird considering the people there use both the new "monster hunter" model and the regular one.
The old Human males are supposed to be 6' or 180 cm tall. This means the Kul'tiran male in screenshot towers at roughly 3 meters or 10'! To put things in perspective, here's Thor Bjornsson of Game of Thrones fame standing next to some regular people:
Yes, he's much bigger than them, but they still reach his shoulders/chest height. The Kul'tiran looks like regular humans could give him a blowjob standing up. I think Blizzard should tone them down a bit, make them as tall as a Night Elf or Draenei at most. Maybe make the Zandalari a bit taller instead, since that is established in lore.
Unless, of course, they are going the "Kul'tirans still have strong Vrykul blood" route, but this would have to be thoroughly explained in lore, particular the distinction between these Vrykul descendants and the regular humans they are sharing Kul'tiras with. Nobody complained about Jaina being unnaturally tall, unless the size coefficient she gets for being a Boss character is canon now...