I honestly don't know! I don't think it's named after a horse. It's had the same name since it was first run in 1891, but I have no idea what the reason for it is. But that's a really good idea!
Mufhasa's not the first horse to win that race twice, but he's one of the greatest and most popular horses to ever win it. That would be an awesome way to celebrate his amazing career.
Also, the TAB website has introduced live streaming! I haven't tried it out yet, but here's the link:
https://www.tab.co.nz/racing/video