The instructions were given clearly by IRCC prior to the opening of expression of interest system which were as follows:
– Don’t submit the expression of interest form more than once.
– Duplicate entry won’t increase your chances of being invited to apply.
– IRCC will remove any duplicate entries.
An Officer may use his/her discretionary powers that you have tried to misuse the system by submitting more than one expression of interest for the same persons to gain the more chances to be invited. The officer may ask further information from you and your parents which would delay your parents’s application. You should wait for the updates on the application and do not submit unnecessary web form requests to speed up the processing of the application.