I see some others already commented here but I wanted to add my notes in the hopes that it might help others in the future.
A few days before the Superbowl, some Disney blogs speculated that the parade would be in the afternoon, either before, after, or with the 3 pm Festival of Fantasy parade.
The time for the parade was announced just after Super Bowl ended. It was announced for a parade at 2:30 pm. For reference, on this day, there were Festival of Fantasy parades at 12 and 3 pm.
By 1:30 pm, the hub was jam packed. People were lining up down main street. I am willing to bet they were lined up and crowded much earlier than that, but we were in Tomorrowland until that time. I am not sure if the parade started in Frontierland or the Hub. There were lots of cameras set up with staging / interview areas around the Hub so that would be my guess but I can’t be sure on that.
It was warm and sunny and we ducked into the alley near Crystal Arts. We knew we would never get a front row spot at this point and just hoped Jalen Hurts was on a taller float so we could see (he was!). He passed us at 2:50 pm.
My friend got a spot near the flagpole closer to the train station and that was an amazing spot, but out in full sun. I saw many on the train platform and that looked like a great spot too. After the parade, it was a mass exodus as it seemed like 95% of fans left the park at that time. I bet ride waits were low after that!
It was very crowded but people were friendly, cheerful, and not rude. My friends have been to Disney many times included Christmas and New Years. They said these parade crowds rivaled those holidays!
We are not specifically Eagles fans, but we are huge NFL fans, so it was worth it to us to have the chance to see this parade. It was a really fun atmosphere and lots of people were chanting and cheering.
Hope this helps some football fans in the future!