As long as you say Open Mic and the current week it happens to be you're good. Just saying Open Mic will not disqualify you as long as you say Open Mic.
I'm asking people to say "Steemit Open Mic" so when people see the videos on YouTube they will hear about Steemit and possibly investigate it further and I'm asking that we title the posts "Steemit Open Mic" so it will rank on search engines. The more people we have joining Steemit the better it is for the platform so since we're making these videos anyways we may as well promote Steemit too.