I can give you some input on this
It is my understanding that the Transfered stats currently includes uploads, downloads and server-side copies.
The server-side copies were added as result of this forum thread:
B2 server side copy doesn't show cumulative progress - #12 by ctonsing
There is a pending issue to include server-side moves:
--stats-one-line-date does not increment transfers when doing a server-side move · Issue #5430 · rclone/rclone · GitHub
Personally, I can see many good reasons both to exclude and include server-side stats in the transfer stats. Ideally they probably ought to be split, but then on the other hand I don't want stats to be too complicated to code or understand. Still thinking...