Cloned feed importer doesn't retain 'Attached to' setting when default importer is disabled

Sorry if this is a dumb/newbie question, but I've noticed this odd behavior...

1. enabled the default 'Feed' importer
2. made a clone of it called 'myFeed'
3. 'myFeed' inherited the 'Attached to' settings
4. disabled the default 'Feed' importer
5. nothing displays under 'Attached to' for 'myFeed'
6. the 'Feed' and 'Feed item' content types disappear

Is this normal behavior? Shouldn't cloned feed importers retain the 'Attached to' settings?

After disabling the default importer, the 'Feed' and 'Feed item' content types aren't there, but the cloned importer still points to them. So, shouldn't they stay enabled? If this is not possible, then I believe that during importer cloning there should be options to set these to. Perhaps pre-populated text fields so people can have the chance to either leave values inherited from cloned importer or change them to custom ones.

Also, I don't know if this matters in any way, but I've noticed this difference between the default importer and the cloned one:

default 'Feed' importer:

  'fetcher' => array(
    'plugin_key' => 'FeedsHTTPFetcher',
    'config' => array(
      'auto_detect_feeds' => FALSE,
    ),
  ),

cloned 'myFeed' importer:

  'fetcher' => array(
    'plugin_key' => 'FeedsHTTPFetcher',
    'config' => array(
      'auto_detect_feeds' => FALSE,
      'use_pubsubhubbub' => FALSE,
      'designated_hub' => '',
    ),
  ),