If they decide to cover just one model, why not make it their most high end HEDT processor?
That's one model that doesn't need it. Users that actually need a cpu like that should be prioritizing system stability over what meager gains - if any - they'd get.
Now they gotta spend time doing trial and error to make sure what they applied is as stable as possible - time that their machine isn't making them money.
If a BSOD or whatever comes along... whether they lost data or not, that's still time and money lost.
Pro overclockers? That's a niche use for a cpu of that caliber - what happens to that cpu is on them. I don't think the more typical users of those kinds of cpus need to get pulled in to do OC, either by Intel's marketing or social pressure.
Overclock a 9900X? Under custom liquid, sure, because air and hybrid is only going to carry them so far... and that means even more down time when maintenance needs to be done - or a part needs to be replaced... or, god forbid, a leak happens.
I've direct die mounted this 7820X - TG Conductonaut + Eisbaer Aurora 360, all in an H500P Mesh... this particular cpu was binned for 4.6ghz, and I STILL can't keep it reasonably cool under Cinebench R23, Realbench, or Prime 95, Small FFT, All AVX off.
On a cold day using those apps, it lands around 85-90C. I've gotta go the custom liquid route if I want to get 4.6ghz under reasonable operating temperatures.
A Xeon W-3175X? No, just no... Skip straight to custom liquid to OC that, which a typical user of this cpu wouldn't be in a good spot with.