Unlikely to be implemented in my opinion. Occupation is punishing enough for the occupied nation and towns, there’s no reason to punish them further.
Occupier receives:
a portion of all occupied towns upkeep (like 75% or 85% iirc)
100% resource tax on all occupied towns
2% occupation tax on balance (equal to nation wealth tax limit)
I think that’s enough punishment for being occupied.
Additionally this would likely bring more toxicity to these sieges which is not something we want to see.

I dont see how it would bring more toxicity but i think i havent made myself clear enough , occupation tax increases only for the fort so that it pushes it further into occupation and if a revolt fails it will do the same too , this way it would stop the endless loop of the same thing happening over and over.