Only recently (relatively) has Nevada gone from a state-wide code of 702 to 702 and 775. Additionally - by the last paragraph, why then would San Jose have a 4

Only recently (relatively) has Nevada gone from a state-wide code of 702 to 702 and 775. Additionally - by the last paragraph, why then would San Jose have a 408 - if by their facts only states with a single area code for the state had 0 as the second digit?