I kind of wonder if the names applied to rods were intended to market them to a new customer base.
I have been telling anyone who would listen that I would like 7 to 7.5 foot rods in the 7 - 9 wt range because of advantage they offer over longer rods when fighting fish in tight quarters. The longer the rod, the greater the fish's leverage advantage. There are also some advantages in bringing fish to hand when fishing from yaks and tubes. There are casting advantages to shorter rods that help generating tight loops necessary to fire flies under overhanging cover since shorter rods are easier to stop.
TFO already has a 6 and 8wt rods in 7.5 foot lengths.
So these new rods, and similar ones from Scott that cost about twice as much as Sage's offerings have appeal to anglers for many types of situations. The Sage rods saw extensive testing in saltwater environments too for tarpon, snook, and other species.
I will be ordering the "Largemouth" model soon, and while it will be used for bass fishing, it will be used extensively for fishing the local kelp beds where short precise casts to holes in the kelp canopy are often necessary and the shorter length will help with levering fish out or through thick cover.