Sailor Moon's age demographic aiming thing always seems extremely muddled to me. Factors include (but are not limited to):
- The 'animation age ghetto' concept ("cartoons are for kids!")
- Difference between American and Japanese cultural expectations regarding things like what it's okay to show kids, adult hobbyists, gender roles, adult guys collelcting things that seem little-girl-ish, etc
- Being from about 20 years ago (give or take 5)
- Possible inconsistency on the part of the actual developers
- Changing positions over time as the show went on, questions of whether they assumed the same audience was growing up with it versus expecting a new young audience (presumably more of the latter for PGSM)
For example, I'm pretty sure the DiC dub was meant for kids (but mostly got teens and adults). But the original airing of the '90s anime, who was that really meant for? There's a lot of adolescent and mature themes and jokes everywhere and i find it implausible that they wouldn't expect, and indeed partially market to, male 20-somethings in japan who thought it was pretty and wanted to collect figurines and so on. (To say nothing of the transgender audience that was probably not being professionally accounted for properly back in the day, yet was definitely relevant.)
But then who was the manga first meant for? It's got a lot of gruesome death and kinda tricky creepy kissing stuff in the Black Moon arc and other things, so it doesn't seem like a kids thing either, but there seems to have been some degree of intent for that (I think Goldfish Warning errs a lot closer to that, as far as Nakayoshi properties I know anything about, of which there are few).
My best guess is that, at least in Japan, each iteration of Sailor Moon is meant for an entire spread of demographics ranging from older kids to 20-somethings without particular regard for one gender or the other (except perhaps the manga being aimed more specifically at girls than other iterations). I think Japan's broader acceptance of what it's okay to show kids (compared to the US) was a big factor in making the apparent discrepancies gel together. But it seems hard to determine and I must admit I haven't done really good research on it.
In the US, at least, it seems to still get a primarily teenagers-and-adults audience; I don't think DiC succeeded in marketing it to kids, and I'm not sure Cloverway was really trying to.