Verizon official response:
The Cisco Set-Top Boxes will no longer be supported on the network starting in the early part of the 3rd quarter of this year (3Q2024). To make sure there is no interruption in your video service and to provide you with an even better viewing experience, we encourage you to upgrade your current set-top box prior to June 30, 2024. In some cases, a new router may be required. You must have Verizon router model numbers CR1000A, CR1000B, G3100, or G1100 router to use new video equipment.
Additional information can be found here.