Short answer
Not on the numbers. The change did not reduce the engagement parties received, but for about a year their audiences shared their posts more.
What the evidence shows
- The study uses 418,477 posts from 105 party pages and 71 leaders' pages in 20 European countries, March 2016 to December 2019, comparing each page with itself before and after January 2018.
- There was no detectable break in engagement per post, total engagement or the number of posts.
- Shares rose by about 29% while likes, comments and emoji reactions did not change, taking shares from 14.2% to about 17% of all interactions. The rise was found in 17 of 19 countries, was larger on populist parties' pages, and had faded by mid-2019.
- Larger pages lost engagement per post relative to smaller ones, and link and video posts lost ground relative to photos within the same page.
Caveats
The estimates compare breaks in January 2018 with breaks in every other month, but a single event cannot prove a cause.