Summary:
The gamerules "playersNetherPortalDefaultDelay" and "playersNetherPortalCreativeDelay" are not included in Bedrock Edition. They were introduced to Java Edition in version 1.20.3.

https://www.minecraft.net/article/minecraft-java-edition-1-20-3

Added playersNetherPortalDefaultDelay and playersNetherPortalCreativeDelay game rules to control time (in ticks) that a player needs to stand in a Nether portal before changing dimensions

Steps to reproduce:

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

   /gamerule playersNetherPortalDefaultDelay

   /gamerule playersNetherPortalCreativeDelay

Observed results:
There is no /gamerule playersNetherPortalDefaultDelay and /gamerule playersNetherPortalCreativeDelay in Bedrock.

Expected results:
It should be there in Bedrock as Java has it in Java Edition 1.20.3.