It is still necessary to add SSAS to an existing FCI to uninstall and install the instance

Hey
Today I have a productive environment in SQL Server 2017 on FCI (node 1 & node 2). The need arose to install SSAS and also leave it in high availability. However, this environment has a DR (node 3) that is configured with several BAG (Basic Availability Group).
The reference documentation I found for SQL Server 2012 says the following:
If you want to add SSAS to an existing FCI, the only supported way to achieve this is to uninstall and reinstall the instance.
I would like to know if already in the 2017 version it would be possible to just add the SSAS service without the need to uninstall the current environment.