Technically no.
A bot can join any channel.
Some people use a dashboard. (A good way to control/edit commands)
Some people say “go to my joins channel and run a chat command”
This is a good work flow yes. And what I would do if I was running a multi channel bot.
To expand, here
Either use the “join button” to trigger the flow, Since you have the username from being logged in.
Or use get users API to do a token to user lookup and extract the username from that to join on.