Some suggestions of players that haven't been added to the list in the previous years:
Katharina Lehnert (PHL): She retired in 2018 and started working for her former sponsor New Yorker. She's listed as retired on the German wikipedia page and there's also an article in german about her retirement from 2018:
Michelle Sammons (RSA): She played her last pro match in March 2016. In the meantime she was listed as a coach for the Kim Grant academy. I don't know what she's doing right now, but she is listed as "former" tennis player on her Wikipedia page.
Ilze Hattingh (RSA): As mentioned before, she didn't continue on the pro tour and went to the United States to play college tennis. The last info was that she worked towards a career in therapeutic recreation.
Madrie LeRoux (RSA): She played her last pro match at the end of 2018, only playing Fed Cup at the beginning of 2019, since then she hasn't played a match anymore...
Elena Bovina (RUS): I don't know if she's been on a list before. She played her last pro match at the end of 2018.
Valeria Bhunu (ZIM) and Nicole Dzenga (ZIM): They both haven't played a pro match since 1-2 years. The former davis cup team captain said in an article, that zimbabwe lost some promising players due to lack of financial support. They went to the United States to play college tennis with a scholarship, and then that's it. I guess he means the don't return to the pro tour. It seems these two made the same decision as they both seem to play college tennis...
HAVING had Cara Black dominating around the world, for years, it’s sad the country has not had other players following in her glorious path in tennis.
Lesedi Sheya Jacobs (NAM): For her it seems to be the same as with Bhunu and Dzenga. After some promising results on the pro tour she hasn't played a pro match since July 2016. She seems to be playing college tennis in the US, too.
Liniques Theron (NAM): She's listed as retired on her Wikipedia page. She hasn't played a pro match since 2017.