He doesn't encourage it by no means. But I have seen him say on one of his "javascript trap" videos (talking like parent telling his teenager if you are going to use sex, use a condom) that if you find you must, then use the mobile site. I can't find the video, but on https://stallman.org/facebook-presence.html under the heading "How you can communicate safely with Facebook" he writes:

"To make the site work without the need to run nonfree Javascript code, visit to m.facebook.com rather than facebook.com itself."

FYI, currently m.facebook.com now uses javascript, however mbasic.facebook.com doesn't, and is basically the same as m.facebook.com was at the time of his writing.