From ADFS to PTA authentication

Question

Hi all.

I have an ADFS with "Microsoft Office 365 Identity Platform" and other two thirdy part applications (SAP and other) configured as Relying Party Trust.

Now I want to migrate from ADFS to PTA using "staged rollout".

Azure ADConnect was installed with ADFS.

Using "staged rollout" I have verified that users in the group used for "staged rollout" can authenticate to M365 using Azure authentication.

If the same users try to connect to thirdy part applications (SAP and other) they are redirected to ADFS authentication.

My question is:

if now I remove the federation with ADFS from Azure and reconfigure ADConnect to use PTA Authentication instead of ADFS, what happens?

User who need to authenticate with M365 will use PTA Authentication (I guess) but if the same user wants to authenticate versus the SAP application, will he still use ADFS?

To remove ADFS even from the SAP application I think I have to register an Enterprise App for SAP on Azure: is it correct?

Thanks a lot for your comments.