Oh, absolutely!
Super weird feelings after Bradys departure to say the least...
The sentimental fan in me wanted Tom Brady to play his whole career with the Patriots. With the hopes that he could bring them to and win at least one more Superbowl. Giving the Patriots the most Superbowl wins in NFL history then riding off into the first ballot hall of fame sunset! :D I wholly believe Tom Brady is capable of winning another Superbowl. He has still has the drive, motivation, and talent to do it. Whenever it happens, I know he will sign a one day contract to officially retire as a Patriot, but the swan song would've been so much better if he was a Patriot the whole time.
The overly-optimistic/selfish fan in me wanted the Patriots to screw themselves over the next couple years with salary cap nightmares to make a play for some big name weapons like Steffon Diggs or DeAndre Hopkins and some O line protection to lure Brady back, but the realistic fan in me knew that couldn't happen. Unfortunately, the team overall would have been similar or worse than last year if Brady had returned. They just didn't have the cap space to make it work.
It was inevitable though, it had to happen. I'm beyond grateful for the time Tom Brady spent with the Patriots and everything he accomplished, but I'm also excited for the future. We still have Belichick, so I'm still nothing but optimistic. :) I'm also completely bias but their QB Jarrett Stidham is actually pretty good and could end up surprising people this season.
You're right that the division isn't a lock anymore. The Patriots statistically have the most difficult schedule in the league this year, followed by the Jets. The AFC East in general all have tough schedules. The Bills look like the favorites right now but it will be interesting to see how the season unfolds.