Oh, that's pretty standard, I read a story where Midway was operating with another carrier off the Soviet coastline in the early 80s. The Sovs knew about the other carrier while Midways planes conducted simulated strikes against the Soviet targets on the reverse bearing undetected. After a few days or a week of this the Midway revealed herself by intercepting a shadowing Bear, after a week of seeing Tomcats seeing a Phantom with 'Midway' painted on the side made the Soviets go apeshit and scramble everything to find her.
In the Falkland's, despite the CBG being pretty much in the same place for 6 weeks the Argentines never detected them. They only had the vaguest idea of where the carriers were by where the SHars appeared/vanished on the radar plots., not enough to give an SE a chance to get a radar lock for Exocet shots.