You receive an error when trying to open the properties of an availability group. This issue can be reproduced in versions 13.0.400.91 and 13.0.600.65 and 13.0.800.111. The error you receive is as follows:
Cannot read property BasicAvailabilityGroup. This property is not available on SQL Server 2014. (Microsoft.sqlserver.Smo)
This issue was opened for CTP 2 and marked as fixed. It clearly has not been fixed. Here is the item link.