The Perfect Season Collaboration (NFL Timeline)

I was going to make an alternate NFL Timeline that has Patriots over Giants in 2007 Super Bowl (so the Pats get a complete perfect season). Would large amounts of the team retire wholesale, having reached the top of perfection peak and having nowhere to go but down?

Anyone willing to help with that? Repercussions of a perfect season? How this would affect the NFL going forwards?
I could see Junior Seau retiring, but the rest of the Patriots' aging defensive core would stay on until being subsequently traded or allowed to test free agency in the following years.

The biggest change would be what takes place the following season. Defending Super Bowl champions typically play the opening game of the season on Thursday night, and that means the Patriots likely see a different opponent, as the NFL will usually try and schedule a competitive team. In OTL, the Patriots opened the season at home against the Chiefs, where Bernard Pollard blew out Tom Brady's knee and caused him to miss the season with a torn ACL. Matt Cassel managed to lead the Patriots to a very good 11-5 season, but they couldn't win the AFC East that year and actually missed the playoffs. A healthy Brady most likely leads the Patriots to get another division title and a first round bye, and the Dolphins or Ravens are probably left out of the playoffs altogether. The Ravens defeated the Dolphins the following season anyway and the Dolphins are more than likely to lose an extra game or two to the Patriots anyway, so they likely finish a respectable 9-7 or 10-6, but miss the playoffs and instead look to continue building for the following season.

I'm going to say that the Patriots and Steelers finish with identical 12-4 records, but the Patriots struggle with other injuries all year, so they end up with the 3rd seed while the Steelers keep the 2 seed as in OTL and the bye. As a result, a banged up Patriots team barely scrapes by at home against the 6th seeded Ravens, while the Colts, empowered by the presence of Brady in the postseason, come away with the win over the Chargers in their Wild Card game on the road. In this alternate Divisional round, the Colts handily defeat an overachieving Titans team in Nashville, but the Steelers finally exorcise their playoff demons facing the Patriots and come away with tight win over the defending champions as Brady runs out of time trying to drive his offense for a game winning TD. The Steelers host the AFC Championship and once again show their mettle by powering past the exhausted Colts.

The Giants, itching to prove that they are one of the NFL's elite teams and eager to prove their miracle Super Bowl run and stern challenge of the undefeated Patriots last season was no fluke, storm to the top seed in this OTL too. Michael Strahan doesn't retire before this season, so he is still there to lead a powerful Giants pass rush and stifling defense to help the Giants to a 14-2 season, handling the 2nd and 3rd place Eagles and Cowboys toward the end of the season (games the Giants lost in OTL). As a result, the Eagles miss the playoffs at 8-7-1 and the 9-7 Buccaneers take their spot as the 6 seed. The Panthers, Vikings, and Cardinal are respectively the 2, 3, and 4 seeds, leaving the wild card Falcons with the 5 seed. The Vikings manage to defeat the Buccaneers at home and the Cardinals upset the favored Falcons in front of a raucous Glendale crowd. However, the Cardinal magic of OTL is clipped in the next round as they fall short of the Giants. The Vikings defeat the listless Panthers, but get blown out in New York in shades of the 2000-01 NFC Championship Game.

Therefore, for the first time ever, the Steelers and Giants face each other in Super Bowl XLIII, both historic NFL franchises that are owned by families that have married into one another in the Rooney and Mara families. The favored Steelers lead for most of the game, but Eli Manning plays an effective game behind a churning Giants running game and great blocking from his veteran O-Line, which is able to keep Eli mostly upright, and eventually leads a game winning drive in the 4th quarter punctuated by a Brandon Jacobs TD run from 2 yards out, followed by the Giants defense shutting down the last gasp of the Steelers to hold on for a 24-20 win. Strahan immediately retires the next season and the Giants remain competitive the next few seasons, but are never able to recapture the glory of their back to back Super Bowl appearances