The change will affect the indexing of nofollow links. Earlier, Google treated nofollow links only as a mark, so these links did not crawl. In other words, they were not taken into account by the search engine algorithm. This changes on March 1, 2020. From March 1, Google will treat nofollow links as a crawl guide.
Some website owners have used nofollow links to prevent indexing of given pages. Typical pages linked to nofollow can be links to user profiles, links to login pages, links to various sections of the website, or links to external (e.g. sponsored) pages. Using nofollow to block Google from indexing pages has never been a good practice. There are more reliable ways to prevent page indexing (e.g. by adding a meta tag noindex to your HTML).
It is difficult to predict how the update of nofollow link indexing will affect the ranking. This may depend on which Google pages will index. Google can configure the rules for selecting pages to be indexed and not. It has not yet been determined whether Google will decide not to index low quality pages.
A. Read the Nofollow update.
Check what changes Google requires. If the rankings or traffic on your site begins to change, please report this problem to the person managing the website or the website positioning specialist.
B. Analyze the nofollow links on your website.
Incorrect implementation of nofollow can lead to unintended consequences. Check how nofollow links are used on your website and decide if it’s time to remove them and go to the noindex meta robots or to assign them the right attributes.