Hi Jackie,
This post tells us that we will be able to buy replicas with our season 14 payouts, this is what we were told and believed for something around 4 months (I may be off on the exact number of months). But we have not received our rewards with 7.0 and the 7.0 patch notes last minute say we will get our rewards when season 15 starts. If we get them when season 15 starts that means we will not be able to buy replicas with season 14 payouts.