config/default.yml does not match Rubocop of the same version

It looks like this file: https://github.com/airbnb/ruby/blob/master/rubocop-airbnb/config/default.yml must be updated. It has not been updated for 3 years even though `rubocop` dependency has been updated for many times since then.

This gem is dependent on `'rubocop', '~> 0.80.0'`, but `config/default.yml` in [this repo](https://github.com/airbnb/ruby/blob/master/rubocop-airbnb/config/default.yml) is not the same as default.yml in [rubocop 0.80.0](https://github.com/rubocop-hq/rubocop/blob/v0.80.0/config/default.yml). This is an issue because this file lists all cops and supported styles for them. So if one wants to use a style that was added in 0.80.0, they cannot because of the outdated `default.yml`. Therefore, the possibilities of configuration are greatly restricted.

Is there a reason why this file is so old?