Legendary T-mog dagger to sword.

[MageTrainer]

Hello guys, 
I wanted to ask, we used to be able to use legendary tmog npc to tmog daggers to sword ( remember few rogues running assa with azzinoths ). 
So I finally farmed Thunderfury on my mage, and now i´m not able to use legendary tmog to mog my dagger to sword.
Isnt it kind of stupid ? I mean, I can tmog staff to 2hand Axe, so why not dagger to sword ? How long has it been this way ?
Any chance of changing it ?

Thx for answers

[azzo]

lol just checked, cant transmog it too

makes no sense