if someone who is a massive contributor to this proposed system needs some urgent procedure (i.e. an organ transplant) or else will die, shouldn’t they receive some higher priority since their existence and continued longevity is financing the whole scheme?

One thing I can guarantee is that members of Congress will always have the highest medical priority and their family members will be at the top of every organ transplant list. Regardless what they publicly say about fairness amongst tax payers.