@Demo-Hell You're really underestimating how hard and costly it is to translate games like PSO2 or NGS in multiple languages, games that have massive amounts of text and are going to keep being updated over time, which means, they're going to need new translations for many years.
Any additional language that would be added is risky, both in cost and time, and it could result in updates delays. Plus you say that it would quickly pay for itself in new players, but,what if it doesn't pay off?
If it doesn't pay off, they would feel obligated to keep supporting an additional language for many years that isn't bringing new players, it's just risky.
It's a miracle that we're even having PSO2 and NGS in english at all, it took Microsoft helping for the EN version to happen at all.
Also, there's no way russian would take priority over more widely used languages like french or spanish.