That theory suggests that the murderer wanted someone to read the phrase. Nobody could ever read it if the remains were never found. Her body was not buried, nor was there any determined effort to conceal or place at great distance. Look how close the body was to the house. Not even buried. Just laid there next to a path inside a bright white laundry bag. Anyone would think that this place would be one of the first areas searched for her body. The person placing it there must have realized it would be found very soon after any organized search was started. Circumstances produced something else (not officially found until Dec), but the person dropping off the body there could not have anticipated that, could they?
Is the theory that Casey wanted Caylee's body found and wanted everyone to know what the words on her shirt read as?
I don't read it that way at all (forgive pun.) Point is: the phrase had meaning to Casey, and that is all that mattered to her, IMO. Just like the tattoo "Bella Vida." She seems to enjoy her own 'inside jokes.' JMO.