Lol. The lengths people will go to the blame Loomis for things. Loomis has plenty of things to be criticized for without making stuff up. If this was the case, Sean would have told every reporter in the country about it by now while he was telling them how he knew that Mahomes was going to be great.
It doesn't take a genius to figure out that both Sean and Mickey wanted Brees there in case they took Mahomes so that they could keep a good relationship with him and keep him involved. Having Brees in the room wasn't going to stop Sean from drafting Mahomes.