All these articles are a bit misleading, or leave out the basic info that it seems to be the apps used to cast to the google devices, not the devices themselves, that are sending out so many mDNS packets they are choking routers. Specifically it appears to be apps on Android 7/8, that normally sent a query every 20 seconds, but when waking after being suspended, send all the packets they didn't while 'asleep', which can add up pretty fast.
If this is the case, and it seems to be the accepted explanation, I don't see how unplugging your chromecast or Home is going to solve anything. The android apps are still going to search your network for devices to cast to. I could also see how you could have issues without any Google devices, if you using the YouTube, Google Play Music, or other google apps with casting enabled. Seems like disabling the ability to cast on your Android devices, or in the apps would be the real (temporary) solution until Google updates them.