There is no option to rollback proposed list to current active. However, one can download the active report from rule data report and then same can be use to upload the list again with a replace option. One can append new data.
Steps by steps instructions to download the report
Step1: Login to Risk Analytics
Step2: Click on Reports tab on the top of the page
Step3: Click on Risk Analytics tab on the left hand side of the page
Step4: Click on Rules Data Report
Step5: Under rules data report, please update fields Organization name, ruleset name,select list type, select list and check the radio button Active.