@guillaumegaluz said:
Expectation from daily dump of valid ids
Can we expect all the new IDs to be after the highest one of the previous dump?

Yes.
The area IDs (Movies, TV show, People etc ...) are created in a growing way.
The ID of any deleted item is not reused.

All can there be new Ids that are "in the middle"

No.
IDs of deleted items are never reused.

Trying to figure out the best strategy doe dealing with diffs

Obrigado!