It's the same problem that some of the budget socket-AM4 motherboards are encountering. With all of the fancy UEFI programs, budget boards may not have enough space in their BIOS to store configurations for multiple generations of chips. Higher-end boards are more likely to have been equipped with more space.
1. The only x299 boards that were budget boards (like in budget pricing) were the weird ones that only supported only kaby lake x. Everything else was almost 180+ through most of it's life.
2. Even my x299 sli plus which was by definition a budget x299 board (pretty much discontinued) doesn't have this issue.
In fact I took the time to look up other budget boards. All the ones that I looked at, still seem to support kaby lake-x. I mean it's possible I'm wrong... but I'm kind of doubting it.
They also all have 16 MB bios's
MSI x299 raider, Gigabyte x299 ud4, Gigabyte Ultra gaming, Asrock Extreme 4, Asus PRIME X299-A
I know of some evga boards that never supported kaby lake x but I wouldn't exactly count those.
I'm sure some boards fall into this issue, but it doesn't look like nearly as big of an issue as that article makes it.
I7 4930k, 32 GB Ballistix DDRL3@2133 , 1.2 TB Intel 750 AIC, 500 GB mx200, Sapphire R9 Fury, asus x79 ws, HP ZR24w, edifier s730
HP Pro x2 612- i5-4302Y, 8 gigs of memory, 256 ssd