That’s just a fluke… It probably depends on the particular laptop configuration and if they had spare PCI lanes on the chipset or it was easier to just add it to a USB hub or omit it entirely.
New laptops certainly still include SDHCI controllers it’s not like they’ve went the way of the dodo or anything.
I’m just pointing this out as saying that SDHCI is only relevant to embedded ARM boards etc… is not accurate as they are relatively common on a wide range of laptops for at least 10-15 years to present.