Is binding to alias a definite superset of binding to a type parameter?

[Andrei Alexandrescu]

This seems to be an overlook:

https://issues.dlang.org/show_bug.cgi?id=20863

Are there any non-bug cases showing different treatment of type 
parameters vs. alias parameters? I mean:

template xyz(T) { ... }

vs.

template xyz(alias T) { ... }

The second should "catch" everything the first does, and more.