It being effective or not depends on their true intent, which we don't know for sure.
I'm pretty sure F2Pool (China) was already caught censoring transactions multiple times.
- https://atlas21.com/f2pool-accused-of-transaction-censorship-and-vulnerability-in-bitcoin-core/
It is important to me because it's an attack vector and I like to know about these things. If it's not important to you, it's all good 🤝