The first release of the .NET Core buildpack after January 4, 2020 will no longer include .NET Core versions 2.2.x. These .NET Core versions will no longer be supported upstream. Please migrate your .NET Core apps to supported versions of .NET Core before that time.
Additionally, the default version of .NET Core will change from 2.2.x to 3.1.x at this time.
Note: Unless you are manually specifying a version of .NET Core for the buildpack to use, or you have customized your .NET Core buildpack, no action is required.
Elliott Shanks, CF Buildpacks PM