According to their Facebook:
Flattheads, after a lot of difficult conversations that we never thought we would be having, we have decided that in the interest of the safety of everyone involved we will not be moving forward with our Farewell Tour.
Refund information is available at livenation.com/refund. 2020 is still an important year for us as a band and a milestone we want to celebrate with our fans, so please stay tuned for some fun surprises coming your way soon! We love you and can’t thank you enough for being on this journey with us! Thank you for understanding.
Stay safe, Rascal Flatts.