Box fill conductor count
It's confusing, but clear if you read it closely:
(1) Conductor Fill
Each conductor that originates outside the box and terminates or is spliced within the box shall be counted once, and each conductor that passes through the box without splice or termination shall be counted once. A looped, unbroken conductor not less than twice the minimum length required for free conductors in 300.14 shall be counted twice. The conductor fill shall be calculated using Table 314.16(B). A conductor, no part of which leaves the box, shall not be counted.
A wire ending in the box, be it spliced, capped, etc. Counts ONE.
A wire passing clean through the box, no loop or slack. Counts ONE.
A wire passing through the box, with enough slack to be cut and spliced. TWO conductors.
Your question would have two of the first example.
Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.