I went to check and I too have error code 700004 Battle pass can not claim it and I bought the BlizzCon Collection Legendary Pack as well I not seen fallowing:
Diablo IV: Cobalt Ensign mount trophy
Diablo IV: Demon-Mother Countenance mount trophy
Diablo IV: Midnight Harness mount armor
and Lastly the Diablo IV: Lapisvein mount
Can I please have this issue fix soon
I am trying to reach out what is going on here.