It might be able to retrofit it. I'd recommend you speak to autologics or Audi retrofits as members have used them for retrofits and been happy with the results.
I know new q7 models have been arriving to customers without kit such as matrix headlights etc.
We've found this that other manufacturer forums get more footfall. I'm not sure why the Audi one isn't as positive.
Myself and fellow admin team do our best to respond to posts but please bare in mind we are all volunteers who do work full time jobs (I do 74 hours a week!).
Extended warranty is only worth doing if it's a genuine Audi one and not an independent company as most of them aren't worth the paper they're written on.
Your new allroad sounds lovely 🙂
Welcome to the forum you'll find the members on here are a friendly and helpful bunch 🙂
I'd recommend you speak to autologics or Audi retrofits as members have used them for retrofits and been happy with the results
If it happened 3 years ago and not since then I wouldn't be worrying about it. As a rule of thumb no 4x4 should be driven in constant 4 wheel drive on tarmac as it can prematurely wear out the diff, gearbox, driveshafts etc.