The issue with understudies.org is that they rely on others not affiliated with a show to submit the info. More than likely people submit info based on an actor posting on social media if they're out or if an understudy is on. It's not the individual shows that submit it. Also, notice how certain shows never have anyone listed(Wicked, Aladdin, Hamilton, Lion King) on there despite always having covers and swings on. I think the site would be best off if they connected with each individual show to post understudies to be more accurate.
A Chorus Line revival played its final Broadway performance on August 17, 2008. The tour played its final performance on August 21, 2011. A new non-equity tour started in October 2012 played its final performance on March 23, 2013. Another non-equity tour launched on January 20, 2018. The tour ended its US run in Kansas City and then toured throughout Japan August & September 2018.