这是可能的，您可以在config/auth.php中为reg_users添加guard和provider

'guards' => [
    'web' => [
        'driver' => 'session',
        'provider' => 'users',
    ],

    'reg_users' => [
        'driver' => 'session',
        'provider' => 'reg_users',
    ],
],

'providers' => [
    'users' => [
        'driver' => 'eloquent',
        'model' => App\Models\User::class,
    ],
    
    'reg_users' => [
        'driver' => 'eloquent',
        'model' => App\Models\RegUser::class,
    ],
],

然后在你的routes/channels.php中你可以指定你使用的是哪一个保护：

Broadcast::channel('SomeChannel', function ($user) {
    return true;
}, ['guards' => ['reg_users']]);