If you compile against 9.1.1, you should see deprecation warnings (the members are totally removed in 9.2, so there's nowhere to include a message once you're compiling against a later version).
Looking at the 9.1.1 version of the platform,
Deprecated in DNN 5.0. Replaced by by DesktopModule.Version.
RoleController.GetRolesByUser does not have a migration suggestion in its deprecation message (it's just
Deprecated in DotNetNuke 6.2.), but the implementation is this:
UserId == -1 ? new string : UserController.GetUserById(PortalId, UserId).Roles, so it looks like the intention is to retrieve them via the
Hope it helps!