"in the loop/out of the loop"

These are American in origin and date in print from 1970 and 1976, respectively, at least so far as is currently known. In the loop, derives from the use of loop to mean either "A sequence of control operations or activities in which each depends on the result of the previous one" or "a sequence of instructions which is executed repeatedly (usually with an operand that changes in each cycle) until some previously specified criterion is satisfied." The former comes from science and technology in general and the latter is a computing term.

hahaha like whatever..

In the loop came to be used in a figurative sense to mean anyone "in the know" or made part of a process, and out of the loop derives from that.

www.phrasemeaning.com