The point that the traditional games publishing model is bad for profits holds, but the point about environmentalism is ridiculous.
First, high environmental impact would mean nothing for the ability for the GaasS models to draw a profit.
Secondly, GaaS should actually be good for the environment. The alternative to computing in data centers is computing in personal computers and consoles, which leads to worse environmental outcomes both in the hardware itself and in their lower efficiency. Besides, computing in data centers leads to more opportunities for efficiency since redundant computations among different devices and users can be parallelized.
The main environmental impact here is one the author completely misses: the energy required for the bandwidth of streaming videos.