Dude, you justed state they arent gambling, then state all the terrible things they are, which directly contradicts your claims of them not fitting the psychology of gambling, say its ok cause its not the current legal definition (which was created way before this technology to do this existed) as if the legal moral and psychologicals were equivalent, and then support your first claim by saying you don't want your free stuff drip feed to disappear.
There are so many solutions to this problem.
For starters, if overwatch actually is worth playing, they could easily have an affordable monthly subscription, and keep enticing new subscribers, and retaining old ones by releasing content for them to win, in of course MUCH more fair and common ways (as the purpose is to keep people happy, and coming back, not addicted and desperately craving that trinket that maybe they can get next time). Thats an actual game as a service, as opposed to games as a slot machine.
But is overwatch really that great if you don't want to keep playing it without new trinkets?
I mean, we played tribes for years because its gameplay was just so damn meaty and engaging, no manufactured drip feed necessary.