This is not really a valid question. Autopatch is a managed service offering that leverages Windows Update for Business (and a couple of other mechanisms).
If your goal is to enable updates for remote devices, this can easily be achieved using ConfigMgr by adding a CMG. You can also enable co-management and move the Windows Updates workload to Intune to leverage Windows Update for Business yourself.
The advantage of Autopatch is not in the mechanism used, i.e. Windows Update for Business, but in the fact that it is a service managed by us (Microsoft) to deploy updates and uses telemetry and machine learning to increase success and satisfaction.
As for your licensing question, there are a lot of "depends" answers so it's best to decide your strategy and then discuss licensing with a licensing expert.