This need not change your play at all.
First, note that players aren't the one to decide when a skill check--perception or otherwise--should be rolled. (See PHB p.174 "The DM calls for a check..." and DMG p.237 for much more on the subject.)
With that established, you--the GM--simply need to decide when it's appropriate to call for a Perception check. If your players say "we search the room and search the bodies," it seems to me that would undoubtedly trigger the auto-success suggested by the authors. If they only said "we search the room" perhaps you call for the check: the implication of a failure is that Lazy McBardalot's dainty toe-nudge at the body wasn't enough to reveal the MacGuffin.
Read the DMG at p.237 a few times, then maybe even read Angry GM's 5 Simple Rules for Dating My Teenaged Skill System (warning: rude and vulgar language mixed in with excellent analysis). You'll learn that checks are for when an outcome is uncertain. You already know these players, so you can easily interpret their self-narration as a casual, moderate, or exhaustive search. Depending on the situation you can decide that a casual search would never reveal the secret compartment (impossible=no check), has an outside chance (DC=20, perhaps), probably will (DC=10, perhaps), or is sure to (guaranteed=no check).
Whatever you do, don't let it slow you down or gum you up. Look at the skills your players have taken proficiency in as signposts as to what they like being good at. Consider how their proficiency (or expertise!) would interact with your setting, and occasionally call for a check.