No specific level. He is already rule 5 eligible. He was not on his organizations's AAA roster so he was available in the AAA phase of the rule 5 draft. Beyond the 40-man roster teams have a 38-man AAA roster to put all their rule 5 eligible prospects beyond the 40-man. It is rare that any real prospects don't get protected here.
Think about it this way. After 7 seasons in the organization players can become minor league free agents. HS and international players are not eligible for the rule 5 for 5 years and college players (or anyone signed at 19 and older) are not eligible for 4 years. So it is a narrow slice of players with 4-6 years experience that are not on the 40-man major league roster OR the 38-man AAA roster who become eligible for a small price ($12,000).
I am sure the Phillies saw something here (not likely big velocity, more likely deception in his delivery) that made him worth a look this season. Imagine he'll be at Lakewood at some point (or Williamsport). If he does not make Lakewood he'll be a 23 year old pretty quickly that has not risen about short season leagues and he is roster filler at that point.