I have noticed this message and the removal of use_thin_lto from the cef/AutomatedBuildSetup in 11/2022.
Well, I just build today with use_thin_lto=false removed from GN_DEFINES and our well known nightmare (read: error 1107 from lib.exe) returned on the distrib phase.
So I retried with use_thin_lto re-added to GN_DEFINES, regenerate projects, build, and voilà the distrib was completed (and libcef_dll_wrapper built debug+release as I'm writing this).
So - is it 5414 the last use_thin_lto version, or is it something else I did not update/did wrong? Someone else perhaps running into this as well?
The build env is pretty much the same, VS 2019 community 16.11.24 on Windows 10 x64, with all Windows SDK versions installed, compilers, runtime - everything as I use normally.