I don’t know where you discovered that but it’s false.
The “Supervisor” is a management tool (distributed as a docker container) that is part of Home Assistant OS and Home Assistant Supervised. There has never been a plan to discontinue it.
Home Assistant Supervised is an installation method that, for a very brief time, was going to be deprecated but then that plan was shelved. It continues to be one of four officially supported installation methods.
“Supervisor” plays no part in Home Assistant’s ability to support IP cameras.
Here are the integrations for cameras.