beyond the 'access' question - if a team was doing something truly different - new formations, new plays, a new defensive scheme - they are going to keep it under wraps until at least the start of the regular season.
college FB coaches all seem to think they are CIA operatives, and everything they deal with has top-secret clearance.
the most you can reasonably glean from Spring practice is a general sense of how practice is run, and maybe some ideas on the athletic ability of individual players.
speaking as a guy who has covered an NFL training camp as a member of the media, most practices are pretty routine affairs.