For historical perspective...
-- 2001 was the last time NCAA's were held on a college campus
-- Since and including 2004, St. Louis has held the championship 7 times
-- St. Louis again is the host in 2021
-- The bid requests in 2015-18 were sport specific, and while other sports were on this cycle, many were not
-- The bid requests system changed dramatically for 2019-2022, with almost all D1, D2, and D3 championship sites bid at the same time. Some sports have other contract requirements, such as Football, and Men's Basketball, so they're not included. This was a massive change, but one that benefitted the NCAA, as they did it all at once, and overall it saved time and energy.
-- For the next cycle, 2023-2026, host bids opened on August 26, 2019, and will close on February 3, 2020. This will be for 86 championships across all three divisions. Announcement of successful bidders (host cities) will be made on or about October 23, 2020. For wrestling, it's possible the finalists will be announced between these dates, we'll see.