Ubisoft have accidentally leaked the date of the next operation and vanity item changes as 6 June 2018. They are also removing some vanity items from previous operations and will likely introduce the Italian operators with the new season.
According to the screen accidentally leaked by Ubisoft, headgear and uniform items from Skull Rain, Red Crow, Velvet Shell, Blood Orchid, White Noise and Chimera operations will become "limited edition" on 6 June 2018. They will no longer be available, but they won't be exactly rare either, as players had plenty of time to purchase them already.
These changes could be a final push by Ubisoft to sell more of these items before the next operation begins, as it will likely bring a ton of new customisation options. Speaking of the next operation, the release date is actually more likely to be 5 June 2018 since every operation so far was released on a Tuesday. The 6 June 2018 deadline probably refers only to the time when cosmetics mentioned above will disappear.
Details on the new operators Alibi and Maestro are still kept somewhat under wraps. Ubisoft haven't officially anything about these two, including the names I mentioned but just about everything about them has been leaked by now.
Alibi will be a female operator whose gadget will be a hologram projector and Maestro will be the fourth wall breaker that complains about Ash's head hitbox. The latter is also the best candidate for the leaked AA12 shotgun and the leaked info so far seems to peg him for a three armour one speed anchor defender.
Weapon loadouts haven't been confirmed for either operator but MX4 SMG and Chiappa Rhino are the top contenders so far, as they are both of Italian make and they've both been found in the game's assets already.
It is noteworthy that the reddit users linked above have been correct about Outbreak leaks, and all description info turned out to be correct, minus the exact names of enemies and such. There is about a month left before operation "Para Bellum" launches so we should be seeing more official info soon.