Hi,
the warning is actually shown even when building an application, this is from a CMake-generated MSVS 2017 solution building the minimal sample:
1>Building Custom Rule E:/dev/Desktop/Lib/wxWidgets-GIT/build/cmake/samples/CMakeLists.txt
1>minimal.cpp
1>E:\dev\Desktop\Lib\wxWidgets-GIT\include\wx/toplevel.h(307): warning C4996: 'wxTopLevelWindowBase::GeometrySerializer': deprecated: Use GeometryStore instead
1>E:\dev\Desktop\Lib\wxWidgets-GIT\include\wx/toplevel.h(293): note: see declaration of 'wxTopLevelWindowBase::GeometrySerializer'
1>minimal.vcxproj -> E:\dev\Desktop\Lib\wxWidgets-GIT-build-vc15-x64-dll\lib\vc_x64_dll\minimal.exe
1>Done building project "minimal.vcxproj".
This happens with MSVS 2015 and 2017 but not 2026.
Best
PB