This doesn't have anything to do with IPv4 vs IPv6. It is a routing issue with BGP. To give an analogy,
if every website were a house,
and every house has a house number (IP address-- either IPv4 or IPv6),
and a group of houses form cities and towns that can be identified by a number (AS/ Atonomous System number),
the highways between cities are similar to BGP routes,
and if half of the world's internet traffic goes through the city of Centurylink (AS3356),
If the city of CenturyLink (AS3356) shut down traffic, either on purpose or on accident.
...then it doesn't matter if your house number / IP address is a 32bit number or a 128bit number because traffic needs to take a different route.
This is what everyone is worried about BGP routes, not IP addresses.
if every website were a house, and every house has a house number (IP address-- either IPv4 or IPv6), and a group of houses form cities and towns that can be identified by a number (AS/ Atonomous System number), the highways between cities are similar to BGP routes, and if half of the world's internet traffic goes through the city of Centurylink (AS3356),
If the city of CenturyLink (AS3356) shut down traffic, either on purpose or on accident.
...then it doesn't matter if your house number / IP address is a 32bit number or a 128bit number because traffic needs to take a different route.
This is what everyone is worried about BGP routes, not IP addresses.