If you do not know what an "embargoed press release" is then read below. The section below is from the linked article.

"An embargoed press release is an announcement that is shared with journalists prior to a specific publishing date. It is commonly used by PR professionals to give their media contacts enough time to prepare a story before the news breaks, which can be highly beneficial for both journalists and PR pros."

https://www.pr.co/blog/best-practices-for-embargoed-press-releases