Blog covers all things for Microsoft SQL Server

  1. AlwaysOn Availability Groups
    Nope – You can use failover groups and active geo-replication instead of AG groups.
  2. Linked servers
    Nope – You can use Elastic query instead of linked servers.
  3. Event notifications
    Nope – You can use alerts instead of the backup command.

This list was taken from Azure SQL Database features 9/22/2017.
Watch for updates as features are added or replaced with alternatives.