Microsoft added a new product family to WSUS server – Microsoft Application Virtualization, that'll include updates for all App-V products include a variety of update types, e.g. service packs, optional updates, critical updates and security updates. Additionally, App-V updates will be available through Microsoft Update and Microsoft Update Catalog. You should sync Microsoft Application Virtualization family if you've these products in your managed environment. Microsoft has made avilable App-V SP2 via Microsoft Update, refer this post for more information.