Forgot about that but yeah it's definitely an issue; quite a few APIs differ in that manner. I never really liked the inclusion of APIs in the TLB, as I've been hit with that issue a lot because of code reuse (individual functions). But I didn't want to break backwards compatibility, so they stayed; I added a few, but almost all uncommon shell APIs.
CopyMemory doesn't appear in the TLB; the biggest one for this issue though might be SendMessage, which does. The TLB, and normal use, have the last parameter as ByRef Any, but I've seen ByVal Long too.

It's still subject to those APIs actually being called though; if there was a Private Declare for one in the form/mod/class, or a Public Declare anywhere in the current project, then the TLB version wouldn't be called. So just adding a TLB to an existing project shouldn't cause an issue as presumably the API not being defined would have caused an error already.