I realize it's not just the Minolta 9. I suspect Minolta used the same firmware / same DOF design in those other models as well.
That this behaviour exists in other Minolta bodies doesn't mean it's the proper thing to do for the camera user. It can be a distraction to others if one is making several DOF readings and they keep hearing the mirror flip.
No other SLR has this "feature" and Minolta eliminated it later. I suspects many would consider this behaviour as a "quirk", if not an outright flaw.
This does seem to be confusing things .
The OP was trying to find out if his new (to him) camera was operating in the way that the manufacturer intended or if the camera he bought was broken .
His Camera is functioning exactly as intended by Minolta .
The cameras that were released from 1993 with the Dynax 700si to the Dynax 9Ti released in 1999 all operated the same way , that's models that were for sale for over a decade all worked the same way . As intended .
The last three cameras they released didn't do this , so what ? it doesn't mean it's a fault .
It's good that there are so many film cameras to chose from now , so if you don't like the way one works , you can get another one .
If you don't like one brand you can get another , it would be very boring if you could only shoot Canon or Nikon , there's a lot of nice stuff out there that isn't just the run of the mill stuff . Where would we be without choices ?
Shoot what you want , enjoy what you have .