You can link a Wahoo account under Settings → Connections, and today that is all it does — it links the account. Sending planned rides to an ELEMNT is what the connection is being built for; it is not doing it yet.
If you ride with a Wahoo head unit now, your rides should still reach us through Garmin if your setup forwards them there. Otherwise, there is nothing you are missing by leaving Wahoo unconnected for the moment.
One thing to know if you do connect: Wahoo expires the connection 60 days after you make it, not 60 days after you last used it. We will warn you before that happens, and reconnecting restores it.
Where this lives in the app: Settings › Connections