Nobody knows either it will be good for Sony or Microsoft, because nobody able to predict the outcome for this project for the future. Would they have better deal with Microsoft instead with others ??? probably not. It's a not a long term plan. The deal can be change anytime. Also Cloud gaming need more than 30 years to become mainstream. Sony can still find more partner , it's just like using Taxi. You can use Uber or u can use other service. Sony not in the hurry or the one in need for the server.
I wouldn't say Cloud gaming needs another 30 years more, these companies want to push it now hence this megaton of a deal that was just made.
Anyway let us be grateful that too major companies are pushing hard to help push our industry forward.