This.
On top of that from what I can tell so far the media isn't ing themselves every time they mention the Eagles. They're certainly roundly being lauded for having the best offseason in the league but there's no massive amount of people declaring them the champs yet either. Honestly I think that's just the nature of covering football. Injuries are such a pronounced part of the game that picking a strong favorite before anyone snaps the ball is at best a roll of the dice. On top of that it's the difference between a game of 5 starters vs. 22. There's way more moving parts on a football field so chemistry is even more important and they are bringing in a lot of FAs in an abbreviated offseason.
And even if they do become every bit as dominant as they COULD be I don't think they'll see the sort of backlash the Heat did. They're a franchise with a long history, in a city with a great sports tradition, and in the last decade they've been good enough that people who were bandwagoners in the McNabb days have been cheering long enough that it's a habit now. Just as the media and the players turned people off on the Heat the nature of their market and fanbase did too. The Heat are a franchise without much tradition so almost all of their fans came across as bandwagoners, especially with celebrities suddenly getting courtside seats and showing up halfway through the second quarter.
Geez, that turned out longer than I planned. Sorry.