A newer Windows Version have no problem with an older NTFS and we have done such migration with just "adding" the old existing VMDK to a new fresh VM a couple of times. There is no answer to the question about what MS have added as features or what happens when enabling Dedup for example on an old ntfs.
Keep in mind that a lot of FileLevelRestore method from all of the Backup vendors works in that way that they just mount an older Windows/NTFS into a current one. So they do the same as you do.
Whats the article from above not covered are the information about the \\shares. The Windows OS keep that information in the windows registry and not as part of the filesystem. So you have to export the stuff from the old system and import the reg keys into the new one or you have to manualy create all shares again. But both a simple steps.
Regards,
Joerg