Verizon might very well be running current hardware. They have announced too many routes which in turn let the global table grow too big which was causing problems with routers all over the place.
The connectivity issue was caused by the routing table to grow too big for old routers used all over the place.
The routing table grew too big because of a mistake by Verizon which might or might not have been running old routers.
It might not have even been Verizon's mistake. When you peer with an ISP it is the customer's router that announces the routes. Announcing all of your networks individually is literally a one line change in most router configs so it's an easy mistake to make. If the ISP is being defensive, and good ones are, they filter incoming routes to make sure they belong to the customer. But they may not have a filter that mandates that they're aggregated since that usually isn't a problem.
The connectivity issue was caused by the routing table to grow too big for old routers used all over the place.
The routing table grew too big because of a mistake by Verizon which might or might not have been running old routers.