Devs saying stuff like this always makes me roll my eyes. I know games have come a long way, but you say a number that hilariously large and I know, it's going to be silly stuff like the game tracking what people are wearing or some crap and they are counting that as a variation. It's just pretty obviously bullshit.
It's even worse than that because once you see that you just know that all they did was add the ability to mix and match ending tidbits like a damn sectional sofa and let math do all the work.
You can get to 16,000 different endings with something as small as 8 different unlockable characters that each have a unique ending.
I see it more as, there's 17k stories to be told. You'll likely never met someone IRL that had the same experience as you. Might have had the same major ending, but the resolution to do many other stories will be different.