I'm normally quick to see moaning fans as brats ("I don't care if BOTW2 is still a year away, I want all the details now! Waaah waaah waaah! I want it! I want it!" stamps feet)
But in the case of BCP, I think the angst is more justified. The difference is that at this point, BCP actually has paying customers. They have paid in full, honouring their part of contract, and are waiting for Nintendo to honour theirs. Based on the information given, a 4 month cadence is not an unreasonable assumption. If there is some irregularity with the release schedule, that's not necessarily a problem, but Nintendo needs to tell their paying customers that.
Keeping them in the dark on when they're getting what they've already paid for is a bit disrespectful in a way that holding back marketing for a game that is still a way off from being sold isn't.