Why is Corneal Collagen Crosslinking (0402T) not covered by BCBSIL even though it is FDA approved and covered under other BCBS state plans?

Apparently this procedure is deemed "experimental" according to the BCBSIL agent I spoke to. It's been FDA approved since May 2016, and is covered by at least eight other BCBS plans,


Would BCBSIL rather pay for a much more expensive corneal transplant instead? Why are other BCBS plans covering this and IL does not?