Aha, totally agreed. Let's not forget too that if you have a Google+ account linked into your YouTube account and have been and will be watching Pokémon Sun and Moon trailers, you'll likely have videos recommended by the likes of Verlis, TTube, Shady, etc., and no offence to any of them, but it often seems beyond a few of the PokéTubers to NOT potentially spoil something in their title/thumbnail.
That's a good point. If I recall correctly - and I may not be - it took a good week or two for them to crack the XY code, though once again, if I recall correctly, XY were one of, if not the, first 3DS games to be decrypted by hackers, as I remember not too long before release data mining talk being shot down as, paraphrase, "it is impossible to datamine a 3DS game - as of this moment".
Oh lord YT is the worst for it. Here's a video about a massive spoiler! The title is a spoiler, the description (that you can see at least the first part of everywhere even in thumnbail form) is a spoiler, and of course the image preview is DEFINITELY a spoiler! Also, all related videos are full of different spoilers. Enjoy the internet