Bloodworth
I don't know if you already got an answer to this, but on Community Showcase you asked if the Octopath Traveler soundtrack is on US stores as well. I did buy a copy of the soundtrack as well and I looked into it a bit more because I put a lot of information on discogs.com.
There seems to be one release which is clearly marketed towards the world. It has both Japanese and English titles for the tracks and it even has a translated interview inside (as well as the Japaense one).
So I think it's a Japanese release that was meant to be sold worldwide.
You can buy it on US Amazon as far as I can see (but I suspect it's an "import"). I have seen it on the European Square Enix Store, so I think they they sell it all over the world (even thought it's the same version as sold in Japan).
I imported/pre-ordered it on JP Amazon a week before the game came out (I wanted the soundtrack after playing the demo). Mine was delayed because it was already sold out apparently (it didn't show yet when I ordered it, so I think I was an hour too late or so). But I only had to wait a week extra. My copy came with an erratum page with a fixed tracktitle, but later copies apparently don't (I got this from somebody on discogs).
I'm unsure on how easily you can get a copy nowadays, but from what I have seen before with other games, Square Enix is rather good in keep producing copies of their soundtracks (I bought the Nier:Automata soundtrack after GOTY's last year).
I do usually import them from the JP Amazon site because it's usually cheaper compared to ordering from European stores (you can set JP Amazon to English, so it's not even a hassle to navigate), but I think US Amazon sells them as well (not sure what's cheaper in that case). It also arrives quickly when I order at JP Amazon. It's usually faster than ordering stuff from a UK or NL webstore, which is insane as I live in Belgium.
There are cheaper JP stores to get them, but then customs sometimes flags the packages which makes them a lot more expensive (as they charge 30+ euro extra). For Amazon JP I pay a little bit more for customs (usually 8 - 16 euro), but it never got flagged after that). I don't know if that's a problem for the US or how it works over there.
I never tried the Square Enix store, but I guess that is a good way to get them as well.