Many members on this forum have mentioned that your English test scores and assessment results must be dated BEFORE your ITA. Receiving either of these after your invite may lead to a VISA rejection. Having said so, these were cases for primary applicants. But since you are claiming partner points; I am only assuming that will be case for you as well.
I feel submitting the new assessment report may lead to a rejection. Maybe you can just submit the old one as of now, and wait for the CO to ask for new one. You can contact the DIBP to clarify the situation, maybe.
Whatever you do, be absolutely sure before proceeding.