The article specifically calls out LED filament bulbs, but those bulbs aren't designed to actually output blue light to the user, they output the light that the phosphor coating on top should output, which is usually yellowish at 2800K. Are they talking specifically about LED bulbs and displays that still use separate RGB LEDs?
Warm white LEDs still have about 30% of the blue light emission that cool white LEDs have. I really think the article is talking about cool white primarily though.
AFAIK that’s always the case - a “white” LED is simply a blue diode + phosphor. They can still output a lot more blue light than an incandescent lamp, even when the resulting color temperature appears to be the same.
