My thoughts take em or leave em
Silver should get to board with zone one or at least before the credit card types. Half the plane is zone 2 nowdays. Silvers get no respect. 30-49 segments flown is still a heck of a lot more than the casual traveler.
Zone 2 is not just silver and CC it is part of the general boarding. Back of the bus by the windows is also zone 2. So it isnt exactly "preferred" boarding
Exit row does not get zone 1 or 2 automatically or preferred boarding. It may seem so becuase usually its elites sitting in the exit row.
On lots of my flights as of late the GA have been calling preboards then First Class then preferred including "chairmans platinum gold silver and star gold and silver" so you get to board with Zone 1 even if your BP says Zone 2 just as long as it says silver on top.
I also have seen an increase in Zones 6 or 7 or whatever boarding with Zone 2 as some GA just dont enforce the rules.