You know this is similar to a question I’d like to ask Belichick, which is how much they have to take in factors like potential in-season matchups into account going into the season. For a simple example, if a divisional opponent is stocking up on big receivers, do you try to counter that move with bigger corners? Something along those lines.
Back to your question though, I think the schedule is different every year with a mix of teams you’re familiar with (divisional opponents, good AFC teams like Indy/Baltimore/Denver) and teams you haven’t seen in a while like the non-conference games. Of course you always need to see what teams with new coaches are doing differently and there will always be some turnover that shift a team’s capabilities.
But the most important games are the ones against the teams that you’re generally most familiar with so I don’t think Belichick himself spends much time in-season looking down the line. Publicly and privately with the team I think he maintains that “one game at a time” mantra, but you can count on the Patriots scouts being deployed to keep an eye on who’s coming down the pike, especially divisional teams that have changed coaches or major players.