As far as I know, the 1.0 base game codes still work and you'll get "A Realm Reborn" for a new service account and 30 days free playtime. Or it can be added to an existing service account if that service account is PS4/Mac only (no PC licence yet). This behaviour (both examples) is exactly the same as when you purchase a PC version of 2.0 though so nothing really special there.

However, 1.0 had separate codes for the extra items (Standard = Garlond Goggles, Collectors = Onion Helm), but sadly according to SE neither of these are able to be redeemed any more.

So basically since you can't use the extra item code any more, it's essentially the same 2.0 ARR that could buy, just in a different box (but don't even try and install from the included DVD, you have to download it!)