https://www.npr.org/2010/10/09/130451369/the-zombie-network-...
But yeah, this is basically it. We could detect the signal, but they simply aren't emitting a signal in the right direction for us to detect.
Hams already talk to the ISS on the 144-148 MHz band (which is close to the FM radio in your car). They have about a 15 minute window to talk to the ISS. They have a 90 minute orbit, too, so I would bet similar window to talk as Artemis II.
The ISS is much closer to the earth than Artemis. Quick google tells me the Artemis is 184 times the distance as the ISS (dang!), bit inside the Van Allen belt. Our atmosphere is transparent to 2.4 Ghz, so there probably won't be too much attenuation. You would need to account for scattering of the signal - maybe use a yagi directional antenna?
In conclusion: I bet you could interfere with their wifi, but might not be able to hear their signal
Seems unlikely. Even at perigee, a long boom YAGI 20 degree spread would be ca. 40 km wide. Mind you, the signal would still be 5 million times stronger than when Artemis II is close to the moon.
Edit: Anybody know how difficult it would be to keep an antenna pointed at them? I have no intuition for how fast their transit would be. I assume, since an orbit is around 90 minutes, pretty damned fast.
Edit 2: Some search-engining and back-of-the-envelope not-very-good-at-trig math says the longest possible transit would be about 5 minutes, moving though about 40 degrees of arc / minute. I'm probably completely talking out my ass, though.
It feels like it would be do-able to keep a directional antenna trained on a target moving at that speed.