Right now, for engineering, what is happening is the revamped performance review process running its course. As with every year, the target for "needs improvement" is 10%, which is not new. Those going on "needs improvement", in the past, did not all go on PIPs. Also, PIPs at Facebook have not been nearly as draconian as at Amazon. With all these details, I find it a very strong stretch to say that "15% of Facebook's workforce may lose jobs."
Originally I wrote in a lot more detail about all of this - and why the Business Insider article likely doesn't apply to engineering - behind a paywall. Seeing this trending on Hacker News, which article I find misleading - an article referencing a public Blind post! - I un-paywalled my reflection, and my own analysis on the situation at Facebook. I personally doubt there is a need for layoffs at Meta, and I'm surprised no other publication points this out. Analyzing the financials gives a very different picture on whether or not any form of layoffs would be needed.
My response / reflection: https://blog.pragmaticengineer.com/meta-layoffs/