Should the hash code of null always be zero, in .NET

Question

Given that collections like System.Collections.Generic.HashSet<> accept null as a set member, one can ask what the hash code of null

Answer 1

Tuple.Create( (object) null! ).GetHashCode() // 0
Tuple.Create( 0 ).GetHashCode() // 0
Tuple.Create( 1 ).GetHashCode() // 1
Tuple.Create( 2 ).GetHashCode() // 2