It’s important to look at the data for Requests for Evidence (RFE’s) to determine, among other things, the level of the government’s combativeness with particular types of immigration applications and petitions.
The RFE numbers for petitions for O visas have been rising year over year, a trend that became noticeable in fiscal year 2018.
https://www.uscis.gov/sites/default/files/USCIS/Resources/Reports%20and%20Studies/Immigration%20Forms%20Data/BAHA/non-immigrant-worker-rfe-h-1b-quarterly-data-fy2015-fy2019-q1.pdf