At least the few that received them recently seem to be unique, since they did receive scholarships in their first year.
I believe that leaves the scholarships as protected as any non-walk-on's.
15.3.5.3 Reduction or Nonrenewal Not Permitted—After the Period of the Award. [A]
If a student-athlete receives athletically related financial aid in the academic year of his or her initial full-time enrollment at the certifying institution, the following factors shall not be considered in the reduction or nonrenewal of such aid for the following academic year or years of the student-athlete’s five-year period of eligibility:
(a) A student-athlete’s athletics ability, performance or contribution to a team’s success (e.g., financial aid contingent upon specified performance or playing a specific position); (b) An injury, illness, or physical or mental medical condition; or (c) Any other athletics reason.