Default behavior of browsers is to open a link in the current tab. Checking the box for “Open link in a new tab” breaks the default behavior of the browser.
In addition, it breaks the back button, which is one of the top 10 functions used in a browser.
Screen readers don’t always let users know that the page has opened into a new tab.
It is best not to use this feature although it will not show you an accessibility error. It would be considered a usability issue.
There is one instance where opening in a new tab is helpful, when users need to gather information or transfer information from one webpage to another. Being able to go back and forth between the 2 tabs would be convenient.
Letting users know they are opening a new tab would be the best practice if you must open the link in a new tab.