So what's the alternative? Never change anything?
Of course not. But the best course forward is going to be different for different folks. What might work best for me might not (probably WILL not) work best for everyone else. One has to look at their situation and plan the best path for their business with their architecture and the resources they have available to them. I suggested one option but that might not work for others. Others might see a strict white listing, or maybe some combination of the two. But there is so much brokenness out there right now that I would hesitate to trust an AAAA request that arrives over v4 when there is a v6 name server available.
Remember, this is al extremely trivial stuff: most things won't even completely stop working. And a few mouseclicks (yes, you have to know which ones so the helpdesks better start figuring that out) and you're back to normal. Compare this to turning off analog TV transmitters
that
have been running for decades where people have to buy converter boxes and sometimes even install antennas on their roof to keep using the service.
It depends. There are other things to take into account. If you increase the time it takes a mobile device to complete a transaction by only a couple of seconds, if you multiply those couple of seconds by all of the users in a large metro area, you end up with devices increased use of network resources (and increased battery drain on the devices themselves). Anything that can be done to speed transactions up and get those transmitters shut off as quickly as possible is a win. If you don't have a lot of mobile clients hitting your site, then maybe that isn't a problem. Every network has their own set of resources and their own set of challenges and all of that has to fit within the network architecture they have deployed and their business model. Basically, there is no "magic bullet".