Explanation
Yes. Meta can use photos shared through Facebook within the permissions and policies that apply. This does not mean that it becomes the copyright owner or gains unrestricted rights over every photograph on your phone.
Facebook's published explanation distinguishes ownership from permission to display shared content. Meta also describes using adults' public content to train AI, including in its European Union announcement. That announcement provides an objection mechanism for EU users; it should not be treated as a universal description of controls available everywhere.
Photos stored on a phone require a separate distinction. Meta's camera-roll suggestions feature is opt-in. The company says it does not use that camera-roll media to improve its AI unless users publish it or share it with an AI feature. The relevant conditions therefore depend on where and how a photo is shared, the feature used and the user's region.
Key takeaway
Meta can use shared photos, but usage rights, copyright ownership and access to a phone's camera roll are different matters.