Congrats
Note that you do not need to receive the IELTS score report or ECA in the mail to update your EE profile. You just need to grab the TrfNumber at the bottom of the page showing the IELTS score online, and the ECA# from the PDF that WES posts online. So you can update your EE profile and get the extra points right now instead of having to wait for the snail mail.
And yes, you are right to prepare your documents for OINP now instead of waiting for a NOI. Almost everything that you need to get for OINP you will need post ITA anyway (only your birth certificate and letter of intent to reside in Ontario are required for OINP but not for the federal system post ITA). So once the OINP system opens again, you will be able to submit the moment you receive NOI, unlike me. I received my NOI on July 11, frantically and diligently started gathering my documents right away, but was not ready to submit until July 25, a day too late, and I am kicking myself every day for that!