Taboola’s “Read More” feature shortens the viewable length of an article and raises the visibility of below-the-article units, encouraging user interaction. This feature generally leads to a 20% or more uplift in interaction with these units, and won’t affect your SEO.
The “Read More” feature shouldn’t have any effect on ranking or indexability, since it follows both web standards regarding hidden content, and Google’s policies regarding hidden content.
If you’re concerned about how the “Read More” feature affects ranking or indexability in the age of Mobile-first Index, Google has stated that features like this won’t prevent the full article text from getting crawled and indexed.
Google’s representative Gary Illyes stated at a conference (2017) that:
“... content hidden behind “read more” links on a page via CSS will still be able to rank in the mobile-first index.”