The lockdown system allows you to lockdown channels inside your server. You can setup a dedicated role for the lockdown system, whether to hide the channel upon lock, or ignore channels from the lockdown all function. Aside from most bots defaulting for the @everyone role, this provides customization.
Upon using lockdown all, you may want to ignore certain channels. With this, you can do it. If you wish to remove an ignored channel, just re-execute the command.