I believe they still do. But why would they license or give them to other companies? Especially their direct competition (Nvidia), which are literally their enemy.
It's kinda like how we see no amd laptop with intel NICs. The few rare times we see it it's usually from some small boutique manufacturer (e.g. minisforum or something) doing it. I'm guessing that when or if amd approached intel for their NICs either, intel either would say no or given unfavourable terms like charge substantially for it making it unfavourable.
This is all wild speculation on my part. All this stuff happens under NDAs, I have no real evidence, so just my 2 cents but that could possibly be the underlying reason.
There's still broadcom, which is used in MBPs. They could possibly use that maybe still.
Worse case scenario, even if Nvidia really do go mediatek.. I hope they write their own wireless drivers for it. The past Tegra's had great linux support so maybe it could be done.
If all fails as a last resort, and wlan chip is soldered un-upgradeable, I guess I would just either use an external wireless usb adaptor or wired ethernet..