This is a good time to eliminate unwanted branches because there will be no bleeding, but not good for back budding (as you discovered).
Cytokinin hormones are made by the roots and drawn up the tree through the xylem (wood) by transpiration. Cytokinins release buds. Auxin that is produced by the branch tips and goes down the tree in a bucket brigade from one cambium cell to the next, suppresses buds. These two hormones are antagonists, countering the effect of the other.
In the active growing season the levels of both of these hormones is high, so we back get bud release when we prune because we eliminated the auxin source on the branch. In winter dormancy, the level of both hormones is low. So pruning in winter doesn't produce a situation where the cytokinin level is enough higher than the auxin level to release buds --> no back budding.
You can find more about this in the
articles at evergreengardenworks.com .