Yes and no. You'll need a gateway address for every NETWORK (defined bij the submask) you connect to. If your ip is within the network of your previous ip (and that's true in this case), you don't need to add the gateway.
But if your provider would give you an extra network connection to e.g. an internal backup network, you would most likely need the add the gateway.
So, it's not related to the provider, but the network. One provider can have many different networks available for it's customers.