Deprecating legacy entitlement values?

I was told by someone that IDM 4.7x is deprecating entitlement values of Legacy, and only idm4 will be supported.  I am trying to track down a reference to this.  Any ideas?  I have not seen this written anywhere.

 

I went through the 4.7, 4.71, 4.72, and 4.73 release notes about deprecations and no reference.

The DTD for EntitlementConfiguration still lists legacy and idm4:

https://www.netiq.com/documentation/identity-manager-developer/dtd-documentation/entitlementconfig/entitlement.html

Anyone run into this issue?