It is best that rolled fondant be frozen for the short-term only.
Sugarpaste is affected by the humidity of freezing and the condensation of thawing. It is easily "dissolved" by the moisture in the atmosphere, making it sticky and gummy. Make sure your cake is thawed before removing the wrappers. Some brands of rolled fondant may freeze and thaw better than others.
For example: We freeze the top tier [fruitcake] for consumption in the time after the event 4-8 weeks. The cake, thawed properly in that time-period, would probably be okay.
We freeze the top tier long-term [could be years] for a special occasion such as the first anniversary or a christening. In this case, the original rolled fondant would be removed [would be inedible] and the cake would be re-covered.
When the cake is being kept for extensive periods after a wedding, changes in the appearance and texture may not be as important to the consumer as the eating.
The edibility of the icing depends upon the icing itself, how the cake is wrapped/contained, the freezing unit used and the storage environment is maintained.