Hi @PwncssPeach,
Unfortunately, I don't really think there is a bulk way to do what you'd like at this time.
While I understand your methodology, it really does somewhat go against the way the missing tag is designed in Canvas overall, and it may cause some confusion for students or parents who read Canvas guides. You may already know this, but the missing tag is really meant to convey to everyone that the assignment hasn't been submitted yet, but not really whether submission is still possible. Adding another status might not be a terrible idea if it were done globally, but in a single class scenario I do think a new tag or removing the tag is going to send some mixed messages to student.
I know this is extra info that you didn't really ask about, but I just wanted to at least say that in case its helpful in the thought process.
-Chris