This isn't right. The text expressly provides for a DM to decide if there is challenge present that makes what the player determines, uncertain and thus require a check. I thought you had conceded this point!?If they are taking all the text of the rulebooks into consideration, they would find that no, it can’t succeed because how the character thinks, speaks, and acts is up to the player, not the dice, to determine. So no ability check is supported in being called for.