Single Player Map Idea

Lot's of people have completed the single player missions already, and don't care about them anymore. I have an idea that could make more single player maps, without making more single player maps. Let me explain:

Would if after beating a single player map and getting 3 stars, all the defenses in the map (including walls) would upgrade themselves? This would make the base stronger and harder to beat without having to design completely new maps. Of course, the upgraded map would also give more loot for the reward. The map only upgrades itself if you get 3 stars on the previous one. In rare cases, some buildings will be added (mostly storages, and sometimes air defenses)

Let's use "Payback" the first single player map as an example. Payback has 1 lvl 1 cannon, and a town hall. After 3 starring it in the tutorial, it will upgrade itself to have: 1 lvl 6 cannon and 2 storages, and increase its loot from 500 to 1,000.

I think this would be a quicker way of updating the goblin maps than adding new ones. What do you think?