Google judges new keywords based on other advertisers' experiences with them. So, if your new keywords have been historically unable to generate enough CTR to remain active, the likelihood is that they will be tagged in your campaign by either placing them 'in trial' or 'on hold' until your campaign proves its own merit.
But, none of this will matter very, very soon when Google changes its system and keyword states are simplified to 'active' and 'inactive'. eWhisper's thread on the topic has all the information you should need.