I was wondering why GL can't be built for mingw. I don't have a Windows machine here to do tests on and I've never used the mingw toolchain, so I don't know if GL support for nativesdk-libsdl2 would be useful. 

Just in case ... I found out that the only reason for the inability to build opengl, gles2 or vulkan is the fact that mesa is pulled in. virtual/egl, virtual/gbm and virtual/egl are set as rdepends in the PACKAGECONFIG of the libsdl2 recipe. Once these entries are removed, nativesdk-libsdl2 can be built with support for GL.