If you're developing an application with a Windows desktop GUI, you're still doing it on full framework (WPF, WinForms, UWP). They're folding that into .NET 5, and I haven't seen anything indicating that they see that as "doing it wrong". This is only one case of developing for full framework, but it's a big one. I imagine any other cases where the developer community really needs full framework capabilities that still aren't ported to CoreCLR, they'll fold that in just the same as with the UI frameworks, as a Windows-specific capability. Maybe they end up sunsetting more than I think, but for now this seems more like consolidating Core and Framework than ending Framework.