Yes, the discount is not is not stored in a variable and remembered accross blocks. The difficulty for each block is only based on the previous block, with two exceptions:
- a new difficulty period, in which case it checks the date for 2016 blocks ago
- the new rule
If the fork had happened at the start of the currnet difficulty period, and if the adjustment had kicked in immedidately, the difficulty would be back to normal at the next one.
So I expect the new difficulty will be to be too high. This is because block 477,792 to 478,558 were produced before the fork. That’s 38% of a 2016 block difficutly adjustment period. Roughly 15 minute blocks?
The difficulty adjustment after that should bring things back to normal, assuming hash power stays constant.