Soldato
I think there was a large thread started by Ace Modder about not being able to transfer licenses after a mobo replacement - regardless of OEM/Retail.
This may only apply to upgrade licenses though. I'm not sure how they could justify selling a windows 10 retail version and only have a single use activation out of it.
EDIT: here it is.. http://forums.overclockers.co.uk/showthread.php?t=18684558 have a read.
From the link...seems straight forward...
"If you upgrade from a retail version, it carries the rights of a retail version."