Currently the public plans pay a lower professional fee in most jurisdictions than the private plans may pay; it could be $7 instead of $10. Even though the Morgan study assumed that the revenues would all be the same, in practice they pay a higher dispensing fee for private plans, and certainly cash-paying customers pay more, so there's going to be a loss of revenues to pharmacists.
On May 2nd, 2016. See this statement in context.