Activision has put up a page detailing pre-order bonuses for Call of Duty: Modern Warfare that happens to include cosmetics that are reminiscent of elite sets from Rainbow Six Siege and also point what the microtransactions may look like.
Activision's post about Call of Duty: Modern Warfare preorders has an operator edition that concludes cosmetics for, well, operators. The Operator and Operator Enhanced digital editions will include three cosmetic sets - All Ghillied Up, War Pig and Crew Expendable.
For example, Soap's outfit from the Crew Expendable mission will be used by an operator called Otter, Price's ghillie suit from the Pripyat mission will be worn by Grinch and Paul Jackson's War Pig outfit will be worn by Wyatt.
Keep in mind these operators will not be characters with unique skills like in Call of Duty: Black Ops 4 but they will evidently have some unique cosmetics.
Infinity Ward and Activision have already stated that Modern Warfare will not have a season pass so these cosmetics are likely a way to try and make up for the presumably lost profits. Considering cosmetics don't separate the player base like season pass exclusive maps did, it is a step up, especially if the actual microtransactions follow suit.
On the other hand, this is Activision we are talking about and it's impossible to know how they might screw the pooch. Call of Duty: Black Ops 4's release was followed by positive reviews for the first two weeks at which point Activision decided it was safe to release egregious microtransactions and ruin the experience for everyone.
As a reminder, they charged $9 for a paint on one operator's outfit and sold literal red dots for $1 a pop. It remains to be seen whether Infinity Ward will go down the wacky customisation lane for the sake of selling more cosmetics but past experiences with Activision do leave us feeling uneasy.