SPFL chief executive Neil Doncaster has said that due to Rangers playing a league match at home on March 15, which is the day before the final, there would not be time for broadcasters to cover both matches.
However, McCoist has claimed that Doncaster's explanation is not a valid one.
"Before the announcement of the final venue I did say to the chief executive that if we were allowed to bet, which of course we are not, he should 'get a few quid on it not being Ibrox,'" the Rangers boss told reporters.
"I just didn't think it would be, but that was my own opinion. I think obviously Neil, or whoever is running the SPFL, made the decision and they will stick by it. However, I've worked in television long enough that I know these boys are unbelievable at their job in terms of de-rigging and setting up for games.
"Come on. That doesn't wash with me and I don't think it washes with you either."
The final will be contested between Aberdeen and Inverness Caledonian Thistle.