Its difficult for me to keep straight what $suggestedList is vs $suggestTitles.  Can these be given more descriptive names?  The function names should probably be renamed too.  At this point I can't figure out which are the suggestions the user was last offered vs. all suggestions ever offered.  Maybe something like:

 $currentSuggestions = $this->getCurrentSuggestions( $articleId );
 $historicalSuggestions = $this->getHistoricalSuggestions( $articleId );