On approvals that require majority approval, when the approval count hits "majority approved" status, can the rest of the assigned team members vote before it closes out?

Yes.

There are 2 approval rules when it comes to the number of votes.  Majority and Unanimous.  

Majority vote means that when more than 50% vote to approve then the approval is granted.

Example: If your approval is setup to collect a majority vote:

If you have 5 board members and 3 of the board members vote to approve something, the approval reaches a "majority" status but will still allow the other 2 members to vote even though their votes will not change the status or have an impact on the approval itself. 

Unanimous means that 100% of the board members that were assigned to the approval need to approve it.  If one of the board members does not approve it, then the approval is closed out.