Ah it was a reply to the reply to my reply :D Discourse wasn't able to notify me.
That relaxation makes the requirement of the single generic type parameter completely optional, so you can have 0 to n generic type parameters. So it's best that the types are always matched against value which is strengthened by the access level rules as value has the same access level as the property delegate type. In most common cases you'll be able to omit the generic type parameter list, which is what you initially wanted, but in other cases the user will be able to create more powerful/flexible property delegates.