I have contacted Activision Support, the first time was when the game came out for PS4, and the second time was when it came out for PC on the 29th May. The first time I contacted them, I was told that my information was "helpful" and that it'd be "passed on". - I've yet to have a response from the second support ticket. Subtitles are a must in video games, especially these days. Even though the N-Sane Trilogy isn't dialogue-heavy, it's still something that shouldn't have been missed out on, and whether or not it was intentionally not added, it can still be interpreted as a direct or indirect act of discrimination for those who require it. Those who have purchased the product and require subtitles are not getting that accessible right. There are petitions for subtitles to be added to the N-Sane Trilogy, and quite a few posts on various forums regarding this matter, yet there hasn't been any official response from any Activision staff member to highlight the issue and what they're going to do about it (if anything). I only hope that the Spyro Reignited Trilogy doesn't follow suit and that the Crash Bandicoot N-Sane Trilogy adds a patch for subtitles asap.
The Japanese often require subtitles, even if they are not hard of hearing. Due to every word sounding like it has up to 20 definitions vocally.