I don't think it is intended to protect users' privacy, indeed it seems to me that it is against Facebook's interest to protect user privacy from advertisers - the platform is primarily valuable to marketers because of the user data that is available to them.
I think by shutting down the marketplace for 3rd party data, Facebook is allowing it to continue elsewhere but also washing their hands a bit, so next time they will have better optics when explaining themselves to regulators if data misuse hits the headlines again.
I think by shutting down the marketplace for 3rd party data, Facebook is allowing it to continue elsewhere but also washing their hands a bit, so next time they will have better optics when explaining themselves to regulators if data misuse hits the headlines again.