Any plans to retrofit this in the future or does that require a bit of work?
It's likely, but in the context of a more general update, which for KORD is surely planned to cover future expansion of the airport.
Also, are there still MSFS upgrade discounts for those of us who owned your P3D sceneries?
Yes, of course, whenever we released a new product for MSFS that qualifies for a discount for having the P3D version, we sent an email to all user that registered for it. Unfortunately, like with many things related to email, either users change email without contacting us, or our email gets flagged as Spam,
I tried emailing support but didn't hear back.
You emailed yesterday, in the evening ( our time ), at least allow some time before saying "support doesn't reply"