Ubisoft are not really shy about their excessive DRM and people have come to expect just about every game they publish to be always-online. Ghost Recon Breakpoint will be no exception, even when played as a single player experience.
Players choice of whether to play Nomad as a team player or Rambo in Ghost Recon Breakpoint will not affect whether the game is offline or online. In order to play Breakpoint at all, players will on the internet at all times.
Naturally, to people with limited bandwidth or not-so-stable internet, this will be as convenient as a barbed pillow. Oddly enough, Ubisoft chose to name The Division 2 and Rainbow Six Siege as the examples of other games that require connection but didn't think of repercussions of players calling them out because those two games actually have activities that require other people in the same session because they are made to be multiplayer titles.
Ghost Recon Breakpoint even ditches AI squadmates that Ghost Recon Wildlands had so it can really be enjoyed as a proper single-player experience. That is, unless your connection drops for a moment. Then you will have to restart your session.
On the other hand, hoping that the game would not require a constant connection would be too optimistic, given that this is a Ubisoft game. They are, after all, no shy about their DRM usage.
Just about everything Ubisoft has Denuvo crammed into it, on top of always-online requirements. The company's sever allergies are not limited to pirates anymore either as it is now very sensitive to key resellers too.
Silent key activation is the latest novelty in Ubisoft's attempts to maximise profits by excluding less-paying and non-paying customers.
Normally, no one could fault them for that, but inconveniencing the ones that pay the full price on Ubisoft's own store is really not the way to go.