I'm in the UK and I seem to recall at least one instance where my bank blocked a payment to JNC and flagged it as suspicious (maybe because it was a foreign currency), so it would be good to get a heads up email.
I'm in similar circumstances. Where I live, USD is a foreign currency that's strictly managed and I could only purchase the subscription using a special dual currency card with certain hard limits. I suspect that time my bank called me isn't going to be the last and there may well be future instances where the payment gets automatically declined.
I went back through my own emails and I've never gotten an email about subscribing, only emails about purchasing extra credits. It would be nice to get some extra notifications, I'm pretty sure I've seen people indicate they'd like a notice about when credits are spent too since there's no real way to track any of that unless you're meticulously noting every time you spend a credit or get a monthly credit
I get an invoice email from my hosting provider (Digitalocean) every month, a similar email from j-novel would be enough for me. That being said, having more granular notifications would also be great!