Introduction:
I have skin for Keeper of the Grove - Cenarius (or how is called)
Story:
Undead player vs me had no hero skins.
I lunched replay and watched, he made Death Knight before I made Cenarius, appeared like he had skin of King Arthas, and also in that same replay appeared like I had no skin for Cenarius.
Conclusion:
If someone had skins and someone didn’t, everyone would like to replay be truthfull to how things were.
P.S.
Just watching my own replay anytime bug can perform this in various combinations.