I was running small tests in SAS Contextual Analysis 14.1 and SAS Contextual Analysis M1.
I think I did not see terms which were moved to dropped terms coming back to kept terms.
Thing to note may be SAS Contextual Analysis 14.1 user guide pdf has below caution on page 39 --
CAUTION! If concept rules are out-of-date when you rerun any tasks (all out-of-date tasks or topics only), any changes that you made to terms are overwritten with the original terms list.