Shopify is deprecating the processing/rendering of .css.liquid and .js.liquid files

From Shopify Support:
”Shopify has deprecated support for .css.liquid and .js.liquid files. These files are no longer processed or served correctly as CSS in the theme, and any dynamic styles should now be added inline within your section or layout files using tags powered by Liquid. For static styling, continue to use .css files in your assets. Please update your theme code as needed to avoid referencing .css.liquid files.”

I dont understand why no announcement was made about this? Has anyone heard about this?