I suspect all the regulars here are either retired or planning to retire in Japan, so it fits.
Whether temporary residents are shying away because of the name...that is a hard question to answer.
I think this name fits perfectly. I was really excited to see that there was so much content exactly about my concerns at the time.
If it were a name that suggested finance/saving in Japan, I don't think I would have joined. One thing I love about this website, the forum and the youtube channel is that I know it is all from the perspective of retirement.
Some other discord groups I use will give advice about finance or life in Japan, but it is usually short-term advice about 'surviving the X number of years' until you go back home.
You have well to be the best source in town for this topic and I think the name fit this.
I agree with others that RetireJapan is already a fairly known thing among the english community in Japan. Most people that I talk with have heard of it already to some degree (kudos for that!).
I recently struggled with the naming issue myself while starting my own newsletter/blog. I settled for Yen Sensei: Personal Finance in Japan. It sounds super cliche, but hey, maybe that ends up working in my favor.