There is generally no requirement for consent for Meta to engage in these activities in the USA, unless they promise in some document like their privacy policy

There is generally no requirement for consent for Meta to engage in these activities in the USA, unless they promise in some document like their privacy policy to honor the presence or absence of consent for US users. The situation is very different in Europe, for example, where they very much do need consent or one of a few other legal grounds that probably don’t apply to most of their AI training purposes.