Yes and no. The subtitles aren't accessible mostly because of some inappropriate use of web technologies in the Netflix player on the web. There's a somewhat hacky way to still get the subs read though.
Start your video playing, then pause it. Bring up devtools and paste the following into the console:
document.getElementsByClassName("VideoContainer")[0].removeAttribute('aria-hidden');document.getElementsByClassName("player-timedtext")[0].setAttribute("role", "alert")
Hit enter, dismiss devtools and unpause the video, you should now have NVDA toss aria alerts at you with the subs in them. That does mean you get the word "alert" echoed at you for every sub, something that doesn't bother me all that much personally, but you can speechDictionary that away if it gets too annoying.