BROOO WHY DIDN'T THE ML JUST TELL THE MC WHAT HAPPENED...

because he knows how much mc cares abt his pack, and bc he knows what its like being betrayed/mistreated by your pack. His whole plan was to take care of him and keep him out of the gambling den's reach so that he wouldn't have to deal with the reality of the last 5 years having been a lie.
clearly it didn't work but eh, mc is stronger than that (mentally at least)