Rageball server was full most of the time, EU7 is also full most of the time so I don't see why Rageball should replace EU7 DTV. You may not like it but other players do.
But, EU5 New is almost always empty and just takes the space. New players level on DTV because it is easier. Also that HRE server, which is now battle is empty most of the time. But it's not official server and I'm not sure HRE would like to set it up for DTV, less than a week after they arranged it for melee only battle (something everyone seems to be so fond of on forums...)
Yes, we need Rageball server. But replacing DTV with Rageball is not a good idea.