Many in the building design and construction field are familiar with the LEED standard with its focus on environmental conservation and energy efficiency. Lighting efficiency and daylighting has played a significant role in gaining points through this well recognized system.
Now, the WELL Building Standard goes farther in addressing how buildings affect the health and wellness of its occupants. The contribution daylight and electric light and outdoor views are all considered, as is the quantity of light needed during the daytime hours to affect circadian stimulus.
In other words, it is not acceptable to gain efficiency by underlighting spaces occupied by people during daytime hours. While this was never the intent of reduced lighting power densities (LPD) there has been a tendency to reduce illuminance requirements (in footcandles) in some environments like schools mainly to save energy.
Although sophisticated white-tunable light systems are being promoted by some lighting manufacturers, there are also simpler ways to achieve the lighting objectives of the WELL Standard. Yes, rooms will need to have the potential for higher light levels, but dimming systems that do not create noticeable flicker become essential.
I refer you to the following article published by the Illuminating Engineering Society that goes a bit farther in describing differences between WELL and LEED related to lighting requirements.