This is a frequent request year-to-year. Some applicants are asked to submit them; some aren't. I'm not sure any of us (including BGOs) has figured out why the request goes to some and not others. Anecdotally, there does not seem to be any correlation between receiving the request for 7th semester grades and receiving or not receiving an offer of appointment.
Bottom line: I would not take it as good news . . . or bad news. Just another data point. [That said, if your 7th semester grades are a disaster -- as in totally out of line with your first 6 semesters, that could be a problem. Small differences are unlikely to make a difference either way].