There is a rule for speedruns that reads:

Use Experimental Gameplay: OFF

There are currently several runs made in the 1.16 beta. You get that version of the game by setting experimental gameplay: ON

This is breaking the rules and should be removed, no?

Contact the moderators of the game, and send them the relevant runs with details about why they are supposedly invalid.

Message the mods using the site message system or through discord or Post it in the minecraft forums on this site