Zombie-type mobs don't spawn reinforcements unless both `spawn_mobs` and `spawn_monsters` are true

Zombie-type mobs don't spawn reinforcements unless both the spawn_mobs and spawn_monsters game rules are true. This may be intended, but it makes it needlessly tricky to play the game with the spawn cycle in peaceful mode (or completely disabled) and all other mechanics unchanged. I’ve always considered zombie reinforcements to be zombies' gimmick, and feel that the mechanic’s absence is comparable evokers not having their their vex-summoning spell (which works regarless of game rules). However, I understand that some players may feel differently and would expect for reinforcement spawning to be tied to these game rules as it currently us.

Personally I think the best solution would be to have a separate reinforcement_behavior game rule which can be -1, 0, or 1, with -1 meaning reinforcements are completely disabled, 0 meaning they require both gamerules enabled, and 1 meaning reinforcements are always enabled. This is definitely getting into feature request territory, and I would understand if Mojang wished to deal with this topic on a different work track. Nevertheless, I’m reporting this here because I think there is a chance that the present behavior is both unintentional and undesired, give that my own experience would be better if reinforcements always spawned according to the attribute.

To reproduce:

1. Find open sky

2. /effect give @s minecraft:resistance infinite 4 true

3. /time set midnight

4. /summon zombie ^ ^2 ^5 {attributes:[{id:"minecraft:scale",base:1.5d},{id:"minecraft:spawn_reinforcements",base:1d},{id:"minecraft:movement_speed",base:0.05d}]}

5. Switch to survival

6. Punch the large, slow zombie a few times
   ✔ The fight is on!

7. Cheat your way out of the fight with /execute as @e[type=zombie] at @s on target if entity @s[type=player] run kill @n[type=zombie]

8. /gamerule spawn_monsters false

9. Re-run the command from step 4

10. Punch the large, slow zombie a few times
    ❌ The fight ain’t on

Expected behavior

The fight would be on