Yes this does help! Using visual studio 2015 update 2, the 140_xp toolset and the /Zc:threadSafeInit- I was able to build a plugin that loads on Windows XP. So finally I can erase VS2013. The explanation (by Microsoft) on the thread you linked is rather interesting, so I’ll copy it here as well:
Windows Server 2003 and Windows XP have problems with dynamically loading a DLL (via LoadLibrary) that uses thread-local storage, which is what thread-safe statics use internally to provide efficient execution when the static local has already been initialized. As these systems are out of support, it is extremely unlikely for a patch to be created for those systems to add this support as is present in Vista and newer OSes, and we are reluctant to penalize the performance on in-support OSes to provide this functionality to the old out-of-support ones.
To work around the issue you can use /Zc:threadSafeInit- to disable the thread-safe initialization code and this will avoid the thread-local variable. Of course by doing so the initialization code reverts back to the VS2013 mode and is not thread-safe, so this option is only viable if you don’t rely on the thread-safety of local statics.