Will Google or Amazon abandon their obligations to partners in order to mine the CHIA coin?
If the majority of CHIA miners belong to Google or Amazon, then this will become known and investors will sell this coin, which will result in big losses for large companies.
Probably. But they could always mine CHIA in secret, leaving investors in the dark. These companies have a lot of money and power, so the sky is the limit for them. HDD mining isn't as popular as ASIC or GPU mining, so people wouldn't care if CHIA or any other HHD-mineable coin becomes extremely centralized in the future. At least, the idea is there. Making it a success is another story.
Maybe someday we'd get to see an improved version of CHIA that would bring equality to all miners on the Blockchain? If this happens, then HDD mining would become truly decentralized. I was thinking something like a hybrid approach where the coin could be mined with HDDs, as well as, CPUs. It would be something similar to Digibyte with a multi-algorithm PoW consensus mechanism built onto the protocol. The sky is the limit, so anything's possible. Just my opinion

Do you really believe in decentralized mining? Decentralized mining is solo mining, which was in 2010-2012, but when mining pools and adequate profits appeared, many private companies begin to make money on it. And its main goal is to maximize profits.