I am trying to follow this story, which is a bit convoluted and put it together with other mentioned threads. Here is what i have got:
Grandma (OP) had some sort of premonition that a disaster would happen on this vacation and asked about Disney Disasters, worried about how to get to good hospitals, etc even before the trip.
Sure enough, near the end of the trip (next to last day the kids/grandkids would be there, I think) two kids with identical life threatening allergies consumed something at breakfast which set off reactions.
Even though one boy reacted immediately, after one bite of waffle, and very severely, there was time to pull the chef out to the table and no one knew it was the waffles that caused the reaction until he told the family it must have been the waffles.
It just so happens that the two boys are allergic to basically all four ingredients in the normal version of the waffles.
The kid who ate an entire waffle was pretty much ok, but an epi pen was still used and he was still transported by ambulance.
The more affected boy stayed overnight in the hospital (or just daytime? One of many places i am fuzzy on), had steriods, etc but is OK now.
No one from wdw, even though the family were transported to first aid to meet the ambulance and then, presumably transported in a Disney owned Reedy Creek ambulance to hospital, had the son'S contact information until OP gave it to them over a day later when she contacted them after moving from an offsite hotel to YC after her son and grandkids had returned home (possibly leaving a day early? Sounds to me like this might have been the last planned park day with going home the next and if kids were released mid afternoon parents decided to just head home then rather than stay a night just to leave in the morning. perhaps?)
OP doe not think it would be unreasonable to be given an free trip for 6 in a condo with kitchen in compensation for the missed day or so of being at the theme parks together and feels someone at YC should speak directly to her about an incident involving her grandson of whom she is not a guardian?
Honestly, there seems to be a whole lot here which doesn't make sense. OP, I think your stress and worry over seeing your grandchild in distress has probably led to you being confused and not seeing everything or recalling it correctly. I am sure your son and Disney have been and will be in contact and if there is any reason to believe fault lies with WDW they will cover medical cost and unused park tickets for your son and his immediate family.
I hope you are able to get a handle on your anxieties, that you enjoyed your remaining time at WDW, especially the YC portion which was, I think, planned to be just you and your DH anyway, and that your next visit with the kids goes more smoothly.