I don't think that is true. There are specific protection rosters for Class AA and AAA. They wanted to protect Borucki from getting selected in the MLB phase. Otherwise they would have just had him on the AAA or AA reserve list. Is there a rule saying a player must have played in AA or AAA before he can be added to the reserve list? That doesn't seem right
http://www.baseballamerica.com/minors/ask-ba-2/#zm43L2ufxWMODIO5.97
In the Triple-A phase of the Rule 5 draft, teams may select any eligible player left off the major league 40-man roster or the Triple-A reserve roster of 38 players. In the Double-A phase of the draft, teams may select any eligible player left off the major league roster, the Triple-A reserve roster or the Double-A reserve roster of 37 players. In other words, a player selected in the Triple-A phase does not rank among his organization’s top 78 talents, and a Double-A selection does not rank among its top 115. In these cases, players are not required to remain on a particular roster. The player’s contract is irrevocably assigned to the drafting team and the drafting fee ($12,000 for Triple-A, $4,000 for Double-A) is paid.
From the sounds of this teams plug up the AAA reserve roster with the top 38 eligible players in the organization outside the 40 man roster, then the AA roster with the next 37 best eligible players in the organization. This is why, no one good is ever taken in the minor league portion of the draft.