Law professor and former federal prosecutor Arthur Rizer expressed his opinion on this to the Washington Examiner via email, noting his practical concerns:
I do think that this is a religious liberty issue if people got their clergy of choice but a Buddhist could not. If you allow one you need to allow all. I don’t think freedom of religion would mandate the prison to find the clergy type for each person — in fact I could see how that could be a problem. I would just pick the most obscure religion and ensure the clergy would never be available.