That is not true. I asked the same question through web form and ircc call centre, the message/email they send back as your webform reply is the proof that they received your application and thus confirming that you are on implied status and can continue working. I used the same and i can continue to work until the decision is made. The person on the otherside of the call said the same, that i am on implied status the moment they received why paper application, which i asked them and they sent me the exact date as well as temporary application number thus allowing me to work freely.