Drgs may be a little upset and i am senstive to this. Wryms are also thought to be the servants of bahamut; that is the only conflict I see as it pertains to wyrms. However, in skyrim, a loyal dragon served the dragonborn whom freed him as opposed to his superior.
However, adding a puk jug could be a mistake; because the door is open for dragon -esque jug pets. honestly, why should dragoons, whom are not true pet jobs gain a powerful pet while we get a crappy puk. Personally, i would want a naul as opposed to a puk, if a wrym is a no go, I say don't release any dragon jug at all; perhaps they may be best. However, a dragon is indeed charmable.
Dragoons could receive a larger wyvern which possess healing breathes "Shrugs" i do not see why a dragoon could not receive a larger variation of their wyvern while we get the wild ones.
Wonder what SE or devs thinks about this? I would rather see a "There is no plans to add a dragon jug or increase/we will increase drg's wyvern size" as opposed to speculation.