There may be some confusion, looking at all the public documentation for SharePoint, in regard to exactly what is and isn't supported in terms of SAML tokens.
This article https://technet.microsoft.com/en-us/library/cc262350(v=office.16).aspx#plansaml states the following:
SAML token-based authentication
SAML token-based authentication in SharePoint Server 2016 uses the SAML 1.1 protocol and the WS-Federation Passive Requestor Profile (WS-F PRP). It requires coordination with administrators of a claims-based environment, whether it is your own internal environment or a partner environment. If you use Active Directory Federation Services (AD FS) 2.0, you have a SAML token-based authentication environment.
While this may seem straight forward for some, it doesn't explicitly say that SAML 2.0 is not supported. Thus the reason that this question was raised to the SharePoint Product team who writes the code for accepting SAML tokens. The results:
- We support SAML 1.1 and below ONLY
- We support SAML 1.1 with all versions of ADFS (2.0 through 4.0)
If SAML 2.0 will be supported in SharePoint On-Premise at some future time, it is not likely to be in any version that is currently available (2016 or before), but that would be going more into the realm of speculation. Probably the best that can be said is that at this time there are no official plans for supporting SAML 2.0 in SharePoint 2016.