The seems to be no continuity from “Memories Are Made of Bliss”, and “In the Shadow of Zekrom” just starts from scratch and retcons everything.
Pleaselog inorregisterto add a comment.
It is impossible to tell how much time has passed in the Pokemon world between these two episodes, but I will reply with it is unlikely that Ash has done anything important in that time.
There is not normally much continuity between Ash going to different regions. He takes Pikachu, and sometimes one or more of his other Pokemon, and goes off to explore the new region. There doesn’t need to be much continuity there for that basic premise to work.
This making a new start is also shown by having no old Pokemon in Unova (until you get to Eastern Unova, anyway) and (in the games) having the route numbers starting from Route 1 again.