China doesn't require pre-installed apps but the Chinese government require all data processing and storage to be conducted within China with complete source code access.
India chose to back off on data sovereignty [0] because it would have had a side effect of making Indian IT Offshoring less competitive plus to help make negotiating a US-India BTA easier [1].
I don't think there is any reason to assume they would allow forced code execution just because they allow data residency for mainland accounts. And unfortunately, China is likely a much larger and more profitable consumer market than India - presumably they can still export phones produced inside India without this.
This is an interesting point. Is there anyone in mainland china that does do not install WeChat plus AliPay installed? It is hard to live without it! Literally, you can buy a kilo of veg from a wet market stall and pay with AliPay.
So does a security backdoor in every mobile device used by said Indian offshoring staff.