With quantum computing, one is forced to use lasers. Basically, we can't transmit quantum information with the classical light from LEDs (handwaving-ly: LEDs emit a distribution of possible photon numbers, not single photons, so you lose control at the quantum level). Moreover, we often also need the narrow linewidth of lasers, so that we can interact with atoms in the way we want them to. That is, not to excite unwanted atomic energy levels. So you see in trapped ion quantum computing people tripping over themselves to realise integration of laser optics, through fancy engineering that i don't fully understand like diffraction gratings within the chip that diffract light onto the ions. It's an absolutely crucial challenge to overcome if you want to make trapped ion quantum computers with more than several tens of ions.
Networking multiple computers via said optical interconnects is an alternative, and also similarly difficult.
What insight do i gleam from this IEEE article, then? I believe if this approach with the LEDs works out for this use case, then I'd see it as a partial admission of failure for laser-integrated optics at scale. It is, after all, the claim in the article that integrating lasers is too difficult. And then I'd expect to see quantum computing struggle severely to overcome this problem. It's still research at this stage, so let's see if Nature's cards fall fortuitously.
But even more than that, this seems to me like a purely on-chip solution. For trapped ions and neutral atoms you really need to translate to free-space optics at some point.
As for fully integrated optics, it's where quantum computers eventually want to be, and there's no physical limitations currently. But perhaps it's too early to say whether we would absolutely require free space optics because it's impossible to do some optics thing another way.