What they might be able to do is expand this to something like limited texting, or maybe down the line even non-realtime voice messaging.
Google’s Lyra codec can already get down to 3Kb/s and be reasonably audible. It’s not a stretch to imagine within a few years we’ll be able to push that to below 1Kb/s.
Taking those two things together, I think it’s fairly reasonable to assume at least text and voice are within reach.
> The screen showed a color image with high resolution. Looking at it carefully, one realized the thing was a poor evocation…. Kjet recognized Owner Limmende and Jan Skrits, her chief of staff, but they looked several years out of style. Ølvira [the ship] was matching old video with the transmitted animation cues. The actual communication channel was less that four thousand bits per second; Central was taking no chances.
> [...]
> The picture was crisp and clear, but when the figures moved it was with cartoonlike awkwardness. And some of the faces belonged to people Kjet knew had been transferred […] The processors here on the Ølvira were taking the narrow-band signal from Fleet Central, fleshing it out with detailed (and out of date) background and evoking the image shown.
If you use smaller antenna elements you must use a higher frequency, and higher frequencies are more attenuated by the earth's atmosphere (generally, when you get to THz there is a window or else visible light wouldn't be able to penetrate) so they have no chance of making it to a satellite.
If you use less elements you lose all your gain in the side lobes, as the other commenter mentioned