When is Multicast useful?

About a month ago I made it through the original Blueprint networking tutorial series which went through topics such as replication and network relevancy.

This past week I decided to plunge ahead and make it through the newer blue print multiplayer series located here: Blueprint Multiplayer: Project Overview | 01 | v4.11 Tutorial Series | Unreal Engine - YouTube

I noticed the multicast RPC was not once used and yet everything seemed to work fine. Now if my understanding is correct about why it was working it was because in the tutorial series he primarily stored his logic in the GameMode and PlayerController classes. Now I may be mistaken here, but I thought it was a no-no to store gameplay logic in the GameMode. Anyways, if I understand it correctly he runs gameplay decisions on by classifying the event as ‘Run on Server’ and the way he gets data back to all the connected players is to create an event on the player controller classified as ‘Run on Owning Client’.

My question revolves around whether this is the intended work flow when designing networked game play features. If this method works then what is the point of the ‘Multicast’ classification? Would Multicast prove to be more useful when trying to use it in conjunction with a GameState class or would the previous ‘Run on Server’ and ‘Run on Owning Client’ methodology work here too?

Thanks in advance,