Tim Auckland wrote:

To me, the issue hinges on whether the controller thought he was
issuing a clearance based on the traditional method of clearing the
plane to the IAF.
In this case, it's my belief that the controller made a mistake, and
should have assigned 2800 as the altititude.

If, on the hand, the controller was intending to follow the new
procedure of "direct clearance to an intermediate fix", then 2100 is
appropriate, but the controller should have advised the pilot to
"expect clearance direct to the Intermediate Fix" while the plane was
at least 5 miles from the fix.
The OP didn't indicate whether or not he was advised of this.

Good points.