Trapped-ion and neutral-atom QC require lasers because the light signal needs to be coherent. That's the main feature of a classical laser, really. The explanation with the number of photons doesn't really cut it, because even a perfect laser does not have a definite photon number: coherent states are inherently uncertain in both photon number and phase. But LEDs are even worse, because the light signal is truly incoherent. It's not even a good quantum state, it's a classical superposition of incoherent photons that you can't really use for any quantum control.

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.