Summary:
The gamerule "minecartMaxSpeed" is missing on Bedrock. This gamerule is added on Java 24w33a.

• Added new gamerule minecartMaxSpeed that changes the maximum speed of Minecarts
  • Defaults to 8 and goes up to 1000 blocks per second.
  • Setting it to a specific value does not guarantee that a minecart will reach that particular max speed - there are built in air resistances and similar effects that the speed added through slopes or powered rails need to overcome

Step to Reproduce:
Run a command: /gamerule minecartmaxspeed 20

Expected Results:
The command is succeed

Observed Results:
Syntax error: Unexpected "minecartmaxspeed": at "/gamerule >>minecartmaxspeed<< 20"