Ubisoft once again posted the win deltas that judged which operators get nerfed and the changes should kick in after the Rainbow Six Siege maintenance.
Jackal and Jäger nerfs are somewhat similar since both are losing bullets of their mags, in an attempt to make them less combat-effective and rely more on the unique gadgets.
Tracking the opposing players is always useful but Jackal will need to be more careful now, with just 25+1 rounds in C7E. On top of that, the weapon's damage is reduced to 42 from 46, meaning an extra bullet will be needed to take out enemies more often than not.
Similarly, Jäger's 416C will have 25+1 rounds in a mag after the update but it will not straight up lose damage. Instead, this weapon's recoil will be stronger, kicking more vertically than it used to. Granted, this change can result in missed shots and require additional bullet to hit in a duel but once players get used to the gun enough, their muscle memory and skill will likely compensate.
Jäger will also get some nerfs to his ADS, the gadget, in the future but the devs don't have enough info to share right now since the process will require more internal trial and error.
DMRs are easily the least used weapons in the game and Ubisoft are trying to shine some spotlight on them by allowing more optics to be applied. They will now support 1.0, 1.5, 2.0 and 2.5 scopes, in addition to the default 3.0 zoom. This should allow for more versatility and if the map is not that open for long-range fire, DMRs can still be used.