We were asked to sign a form excusing classroom teacher's attendance because she was a required participant. We declined and insisted the meeting be rescheduled. They tried hard to convince us that the principal (ha-ha) would fill her in on what she missed but we stood firm and they rescheduled. I know I am quite jaded but I would say no way, no how to meeting without the teacher.

And about dropping the supports... "Umm... No I don't think so. Let's try adding the math enrichment and see how he does. One we can see how he is handling appropriately challenging work we can see about phasing out some of the supports that have become obsolete. Let's not put the cart before the horse here. You know it's important to set him up for success." Etc...

And as Sweetie said the wheelchair analogy is always effective. Good luck.