Wow! That's an oldie but goodie! I do remember when Eastern was the official Disney airline! That's the airline we flew in 1990 for our first family WDW trip (not knowing it had just filed for bankruptcy and would close less than a year later).
We had arranged arifare, etc through Walt Disney World travel. When we arrived in orkando, there were a couple of characters there (Minnie and Chip, I think) to meet us. At that time, the airlines were serving meals and the Child Breakfast came in a bos with the castle on it, plus a couple of other small goodies.
Our first family trip was in 1990 and we also flew Eastern. I seem to recall some kind of package from them that included airfare and park tickets, maybe even hotel. We met a couple with 2 kids at a family gathering who clued us in about the Eastern deal.
We simply chose Eastern because it was the cheapest flight and used a nearby airport (National) and it was the only time we ever flew with them. We had Magic Kingdom Club room rates through our employers with discounted park tickets and rental car so it probably worked out to be similar to Disney packages.. We really hated to see the MK Club go away!
When were you there in 1990 and where did you stay?