Yes, that the Disney economy is back is a good sign for the economy as a whole, because that people are spending on frivolous extras means that people have money to spend again. The U.S. economy has been doing so well that there is talk of issuing a voluntary correction. They don't talk that way in bad times.
Since Disney is a very expensive vacation and mostly take by the middle class I think this shows that the middle class feels more comfortable with their savings and income levels so they are more willing to splurge on a vacation. I think this means great things for disney as well as the economy at large.
The Disney economy expanding is an indication of a strong and growing U.S. economy. There is an abundance of new high-tech movies that have come out over the past few years and that are coming out soon. Additionally, Disney is investing capital into its theme parks opening new attractions. Disney is making this massive investment because it sees strength in both the U.S. and world economies. So goes Disney, so goes the economy.
No I do not think that the Disney economy had any relevance to the US economy. People may have saved up money to go to Disney or used their tax refund checks. They may also have gone without things to be able to afford to go to Disney. Also it may have to do with Disney advertising to young children.