You are right in thinking you shouldn't talk about it since it doesn't concern you, that is his responsibility to keep those supporting him outside of "a choice few" the reason for his sudden disappearance.
About payment, if you do not use a VISA or MASTERCARD that would be why it works for you but not him. Not even a Japanese VISA works at the moment, this has been the case for a few months now. DLSite, Ci-en and multiple circles have made topics about this (a lot of circles who know they have foreign fans even made post in English to give alternative ways to support). Ci-en support can't do anything to help, now if you're claiming you're using a VISA or MASTERCARD....don't, you will be straight up lying.
So he's gone radio silent for you for 1 month and for those who were (and some he still are) supporting him for 5 whole months. that's not a good image.
Trust begets trust, you can figure out why I'm saying this right?
Huh? Oh nvm, I get it. "he doesn't have an official trial for the game" Honestly, why not? If he was confident in a August release date one month ago, why not give those interested a trial even a small one to boost confidence in him? That's like Marketing: 101.
Again, respect that you want to respect his trust since those are his responsibilities that he has been grossly negligent to. Ci-en is literally made to share progress and stuff about the game to supporters and potential customers.
I'm not saying you're lying, since I have no proof to back that up. But a lot of this just reeks of either misinformation or stupid decision making.