Mira and Maestro are extremely strong anchors thanks to the amount of safe intel they provide but their playstyles will need to change in the upcoming season when attackers get more counterplay.
Mira and Maestro's gadgets proved to be a bit oppressive for the attackers who could only walk into their line of sight without any counterplay in some situations and given the high level of competitiveness in Rainbow Six Siege, this could not fly. Therefore, the balancing in North Star will see these two's gadgets showing some cracks in their armour. Well, glass, not armour.
Attackers will now be able to walk up to Mira's mirror or Maestro's camera and melee attack them. The end result will be similar but there are still significant differences in the outcome. Hitting a mirror will result in it being broken and you will no longer be able to see through it - game over for the intel gathering.
Maestro's Evil Eyes are impervious to gunfire when the protective glass is on but it's this glass that the attackers can now damage. That doesn't render the cameras unusable though. You will still be able to unsheath them and gather intel but that will make them vulnerable to gunfire. You can always retract the camera and return to the status quo where attackers can't shoot it but you also can't see them.
Overall, these changes should a lot of depth to the coming season of Rainbow Six Siege and coupled with the changes to gas propagation, we will probably see some interesting new team compositions.