It sounds like you're on MoCA WAN. If you try to upgrade while provisioned for MoCA WAN, their system will want to send a tech.
If you can run an Ethernet cable between the ONT and router yourself, Verizon can remotely provision the ONT for Ethernet WAN. Then, you can place the upgrade order without a truck roll.
To have the WAN swtiched from MoCA to Ethernet, contact Verizon support via chat, their Twitter support or the VZ Direct forum at dslreports.com. Takes about 5 minutes.