The mid-season reinforcements for Operation Red Crow are live today, bringing Operator balance adjustments, a new map for PvP, weapon tweaks, and most notably, major changes to the lord of the LMG, Tachanka. The beloved defender is the least-picked in the game, so in order to make him a more viable choice, a shield has been added to the front of his turret to protect him from frontal headshots. Though he is still vulnerable from other angles, the idea is to make him stronger at holding angles and to make his stationary position more survivable.
The Bartlett University map, previously available only in PvE, has been tweaked and released into the PvP rotation. The PvE-focused elements have been removed, and changes to map destruction and visual layout have been made to ready it for competitive play.
The update also includes a handful of Operator changes, notably an extra cluster charge and extra battery for Fuse and Bandit, respectively. Smoke's gas canisters now follow grenade trajectories when thrown instead of flying like nitro cells, and Blackbeard, the Operator with the highest pick rate, is getting a few more tweaks. His shield health is reduced and his time to aim down sights (both normally and from a sprint) is increased.
There are a host of weapon balance changes, mainly to address the match-up between assault rifles and submachine guns, and there are a bunch of bug fixes as well. You can read the full notes on this round of mid-season reinforcements on the Rainbow Six Siege official site.