Figured I'd add an addendum for anyone who might see this in the future. If the challenges issue happens again :
1. You will not get any progress on active quests i.e 250 threatening, 250 perilous, 250 completed matches with any character etc etc (i got carried through 5 heartbreakers... and I'm... well...)
2. You will not get any progress on gold collected quests.
3. you will keep whatever promotions you had and probably levels.
4. you will not be able to change banners or portraits until it is fixed.
I might have missed some but just to give people a heads up as to what they can expect next time. Let me know if I missed something or got something wrong. Thanks in advance