Actually, the wifiwave2 contains spectral scan kernel module - it's just not used for anything (yet?).
But main limitation is the version of the radio chipset, AFAIK you have to pay more for advanced version that supports features like spectral scan, phase constellation view and TDMA/GPS timesync and also finer tuning of bandwidth and other parameters. At least that's how it was few years ago. I haven't read any recent Qualcomm documents (mostly because they require NDA to obtain)... but it's clearly not just driver/software issue if the support is not in the hardware...
wifiwave2 is nothing more than an early alpha right now and we don't know what The Big Mik is doing behind the scenes with respect to internal testing of these unused features. I suspect they're going to add support in future (802.11ac-wave2/ax?) models if the current chipsets really are not capable of it. However, with the position they have in the networking world as a super-performance-for-value brand, I'd be surprised if this was actually the case.