Lets compare the current (4+16)*60 format to the (3+18)*56 format. Playoffs format could be different or the same, so I don't count with it now.
4 preseason games: 4*60=240 minutes.
16 regular season games: 16*60=960 minutes.
Overall: 1200 minutes.
3, 56-minute preseason games: 3*56=168 minutes.
18, 56-minute regular season games: 18*56=1008 minutes.
Overall: 1176 minutes.
So every party gets what they want. More games, just slightly more meaningful playing time, less overall playing time, the same number of injuries and more money for players, owners. One additional plus is, games might have a slightly faster pace. And WhoTF cares if the number 14 is not as beautiful as 15 is.