There is no "progressive" definition, income level is not at all part of the definition. Per the universal legal definition of 'affordable housing,' if a home costs $1B but is occupied by Elon Musk, it would still be affordable because it is less than 30% of his gross income.

When you are dealing with income levels it is universally called 'low income housing,' and the HUD definition is already scaled to local income levels, the 'A' in AMI stands for 'Area.'

You are conflating marketing ('we need more affordable housing!') with policy ('low income housing')