Our statistics shows that there are still many ASP.NET Web Forms developers who still develop and support web apps/sites on .NET 3.5 and for the time being we do not plan to discontinue the support for it.
As you can see we distribute .NET 3.5 versions of our assemblies (see the Bin35 folder in the installations) and all new products and functionality work on it.
I also updated the .NET Support page and we will definitely notify the community when we decided to limit the .NET 3.5 support.
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