Meaning:

“官” means “official,” and “宣” is short for “宣告,” which means “notice.” This term caught on among Chinese netizens immediately after actress Zhao Liying and actor Feng Shaofeng used it in a Sina Weibo (a social media platform like Twitter) post announcing their marriage Tuesday. Numerous online posts followed suit, including one posted on Weibo by the official People’s Daily reminding people Oct. 16 was also the 54th anniversary of the successful trial of China’s first atom bomb.

Example:

A: 这两天很多手机品牌扎堆官宣即将出新品。

Zhèliǎngtiān hěnduō shǒujī pǐnpái zhāduī guānxuān jíjiāng chū xīnpǐn。

Quite a few smartphone brands officially announced in the past two days that they will launch new models soon.

B: 好几家不约而同用了流行的摔倒照。

Hǎojǐjiā bùyuē értóng yòng le liúxíng de shuāidǎo zhào。

Several simultaneously posted the popular “falling stars challenge” style photos with their announcement.