DD's Failure to Inform Harry He Would Be a Witness -- OOP

[gelite67]

No: HPFGUIDX 130773

Does anybody have any theories as to why DD failed to inform Harry that 
he would be at Harry's hearing before the Wizengamot?  Even if DD he 
didn't want to talk to Harry in person, he had to know Harry would be 
sweating it. 
 
I can appreciate that DD wouldn't want to give Harry a sense of false 
hope or coach him regarding how to testify, but it almost seems cruel 
to me not to tell him that DD and Arabella Figg were going to testify 
on his behalf.  Surely, DD didn't do it deliberately as a "character 
building" lesson.

Maybe DD was busy with business for the Order and didn't know if he 
would be able to appear?  But wouldn't DD have have made time for 
something so important?  If Harry got expelled and had to surrender his 
wand, how could he ever hope to defeat Voldemort? 

Maybe the larger question is why did JKR have DD not inform Harry?

Any ideas?

Angie