From the press release (https://edpb.europa.eu/news/news/2023/edpb-urgent-binding-de...):
"On 27 October, the EDPB adopted an urgent binding decision ... to impose a ban on the processing of personal data for behavioural advertising on the legal bases of contract and legitimate interest ..."
Under GDPR Article 6, all processing of personal data requires one of the following lawful bases: consent, contractual obligation, legal obligation, vital interests of a person, public interest, or legitimate interests of the controller. The ban says that Meta can't use two of these as bases---contract, legitimate interest---for behavior advertising. Behavior advertising that is consented to is a-okay.