Re: Paranoia speaks:
"I wonder why"
Microsoft's KB article says "A remote code execution vulnerability exists when Internet Explorer improperly accesses objects in memory." so it is probably something like a use-after-free.
If this was in the back-compat cruft then it would be removed when that cruft was deleted from the IE codebase to make the first version of Edge. At the time, they needn't have been aware that the bug existed, or that they'd just removed it.
Biting the hand that feeds IT
