New wireless hub/router

The new router should have at least four Ethernet ports on it in addition to adding WiFi capability. So provided the new router is located in the same location, no change, you will just now have WiFi all over the house.

In general, high quality streamers isolate you from the network and therefore can work optimally from an extender, but if you are close, definitely direct wire your streamer. 

Not really clear what you mean when you say wireless hub? Is it a mesh system like mine below?

I have Xfinity tower with modem and router built in connected by hardwire to the street box. I have a second Linkys mesh system hardwired to the Xfinity tower with nodes connected wireless throughout the house. My Roon core is a sonic transporter connected by hardwire to my mesh tower. One Linkys node (in a different room) is next to my main system hardwired to my network streamer. Additionally, each router can provide a separate network (2) so i have my second Home Theatre system on the Xfinity tower and my 2 channel system on the linkys mesh router. It has worked flawlessly as long as xfinity doesn’t go down. Very happy!

I use an Eero mesh network. I have one of the Eero units in my music room, I plug my Innuos directly into the Eero unit. No problems

They want you to rent a wireless hub. Buy your own. Otherwise, what @carlsbad2 said.

Truth is however that wifi signal quality varies by your neighborhood. If you are in an isolated home in an area that’s not densely populated you’ll have a better Wifi experience than if you are in a cramped apartment. So, yes, get good Wifi, but also hardware things like your TV and stereo just to minimize the chances of interference. Most of my neighbors here use Wifi for all their devices and the TV and the Wifi is not the issue they have.  It's the Hargray service going down for days at a time.

Your wireless hub should still have a port to plug your wired connection to your audio system into.  I plug my hardwire into my wireless router.