The promoter is the one in charge if the match making and should know where his fighters are at in the career though advice of the Trainer. The trainer then should quietly tell the promoter that his fighter isn't ready and not go on tv to public embrass his young gun.
The promoter is the party that gets all parties involved (other promoters, managers, fighters, networks, etc.) to make the biggest money fights possible - you're thinking of the manager's duty to lead his charge through their career and milk as much money as possible. And Atlas made it clear since almost immediately after he became Povetkin's trainer that he needed seasoning - this wasn't some 'grand revelation' that he just revealed to Povetkin at the same time as the world.
Now if the promoter dosen't listen to the trainer, then the trainer should prepare his fighter by telling him everything his does right and everything the other fighter dies wrong and how to take adavagte of it. The key is to build confedence in the young gun and have a plan A,B and C to give the fighter the best chance.
Well, it actually comes down to the fighter deciding based on the information given by his promoter, manager and trainer, so technically it's the fighter's call. If the fighter wishes to disregard his trainer's advice, that's his choice but the trainer is under no obligation to sugarcoat his actual chances - he should provide the gameplans that he could
potentially use to beat his opponent if he's accepted the training gig despite his disapproval.
To me it not ok, for a trainer to every tell his fighter, there a good chance your going to lose before a fight.
It depends on the circumstances - if you're being asked about potential style matchups by the manager/promoter/fighter, you should be honest to allow for the most successful/lucrative path to happen. Additionally, if the manager and promoter are not acting in the best interests of the fighter (particularly the manager who has a direct fiduciary duty to give him the best possible career path), the trainer should provide input so the fighter is not oblivious to the reality of the situation. Allowing the fighter to be exploited by the manager without any input at all would make the trainer comparably liable to any career implosion as his manager, IMO.
Look at how Teddy was able will Micheal Moore to a victory by feeding his ego during the fight, that same attitude should be applied during trainging too.
'Feeding his ego'? Teddy basically questioned his manhood and gave him a 'do or die' notice that he needed to come back strong or face an L against Holyfield. And that was a fight Teddy
was comfortable with (on paper) but that he needed to prod Moorer to go to his potential and gut out against Holyfield in order to become the HW champion; it's a different scenario than tossing a rough Povetkin to the wolves (Wladimir Klitschko in this case) when he isn't close to prepared for the challenge.