Correct

What lenders/loans does this apply to?

Any loan guaranteed by one of the agencies regardless of the lender.  This is MOST loans in the US.  Examples of loans that wouldn't be affected would be FHA/VA as well as certain jumbo and specialty products.  "Non-conforming" loans are not impacted by this as they are not guaranteed by the agencies.  A common example of a non-conforming loan would be a jumbo loan from a retail bank or credit union.

https://www.mortgagenewsdaily.com/news/01192023-big-llpa-changes