Summary:
The gamerules for blockExplosionDropDecay, mobExplosionDropDecay and tntExplosionDropDecay are absent. They were introduced to Java Edition in version 1.19.3.

"tntExplosionDropDecay" was added in 1.21.0.20

https://www.minecraft.net/article/minecraft-java-edition-1-19-3

Added blockExplosionDropDecay, mobExplosionDropDecay and tntExplosionDropDecay game rules

• When set to false, all blocks drop loot
• When set to true, blocks drop loot randomly depending on how far from the explosion center
• Defaults to false for tnt, true for block and mob

Steps to reproduce:

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

   /gamerule blockExplosionDropDecay

   /gamerule mobExplosionDropDecay

   /gamerule tntExplosionDropDecay

Observed results:
There is no /gamerule blockExplosionDropDecay, /gamerule mobExplosionDropDecay and /gamerule tntExplosionDropDecay in Bedrock.

Expected results:
It should be there in Bedrock as Java has it in Java Edition 1.19.3.