Why must I return the chilled chocolate cookie dough to room temperature before baking?
The resting is probably to hydrate to the dough, which will inhibit spreading.  See https://cooking.stackexchange.com/a/29298/14401.

The bringing back to room temperatre is probably for one of four reasons:


To help ensure you are baking each tray at a consistent temperature
Colder dough will cook on the outside a bit more before cooking through, so they may brown or crisp or dry out more than is desired before being cooked through
They might be somewhat easier to scoop at room temperature
The original recipe author was just used to doing it that way.


It is highly likely that by adjusting the baking time slightly, you could bake them from refrigerator temperature, with only a very small change in quality.  You would just have to try it and see.