The first part is why the second part won't happen. Sports generally don't introduce game-altering changes on a regular basis. In the past couple of decades, there's been Major League Baseball's pitch timer... and anything else?
-NFL started replay challenges in 1999 and has since trickled down to all major sports. The major changes to NFL overtime started in 2010 and continue to this day. Also, NFL Kickoffs and onside kicks have been tweaked multiple times within the last 10 years or so.
-College football overtime has been in place only since 1996 and has recently been altered further in 2019 and 2021. And let's not talk about the postseason.
-NHL gave out points for overtime losses in the late 90's, started shootouts in 2005, and went to 3-on-3 overtimes in 2015 (they were 4-on-4 since 1999).
-NASCAR started playoffs in 2004 and in-race "stages" in 2017.
-The current point system for Formula 1 has been in place since 2010 and other recent changes include fuel-free pit stops, DRS, and the introduction of sprint races.
-The NBA's rules against players leaving the bench also would've been within the past 20 years (Malice In The Palace was 2005) and have introduced the Play-In Tournament and NBA Cup within the past 5.