file location of interop.mfilesapi has changed

I noticed in version 26.1.xxxx that the location of the interop.mfilesapi has changed from ..\common to ..\bin\x64 and ..\bin\x32.  Did this change come into effect in this release?  Is it a permanent change?  Our application read the interop directly from the folders, and the location of this file is therefore critical for backwards and forwards compatibility.