OEmbed and WordPress Embed blocks for Facebook and Instagram will stop working Oct 24, 2020 gutenbergtimes.com

Facebook announced in August that they will switch off oEmbed open format and will require a developer and app id for using embeds from Facebook post or Instagram photos.
A plugin in the repository will make the switch easier for larger publishers and site owners, who use FB embeds or Instagram photo embeds often.

What happens when it stops working? The embed will fall back to a mere URL place in your post.