Summary:
There is no /gamerule maxCommandForkCount in Bedrock. In Java Edition 23W41A it has been introduced, but didn't make its way to Bedrock.
https://www.minecraft.net/article/minecraft-snapshot-23w41a

New limit with game rule maxCommandForkCount now restricts total amount of context that can be created by single state of functions like execute
Example: if there are 5 entities in world, execute as @e creates 5 contexts, while execute as @e at @e creates 5*5 = 25 contexts

Steps to reproduce:

1. Enter a world with cheats on.
2. Go to chat.
3. Type:

   /gamerule maxCommandForkCount

Observed results:
There is no /gamerule maxCommandForkCount in Bedrock.

Expected results:
It should be there in Bedrock as Java Edition has it in Java Edition 23W41A.