I've seen Gan for sale in the shop once about 2 weeks ago on server 52, but only once and never Nora or Wraxius. My assumption is they are either,
A) Removed to adjust power
B) Insanely rare on purpose or coding error
C) insanely rare chest drop heroes
Personally I would take Jacques for dwarf even if I saw Nora in the shop unless I could get 2 for the 9.99 price
If you are willing to spend 59/99 however she does look pretty sweet.