Standard humbucker tone = 100% coil A + 100% coil B
Old split tone = 100% coil A + 0% coil B
New bridge split tone = 100% coil A + ca. 25% coil B
New neck split tone = 100% coil A + ca. 12,5% coil B
The portion of coil B in split mode depends on the pickups.
To my ears, the new split tone is somewhere between old split and standard humbucker, but preserves the typical split character.