The PS brand has a global audience. Hec they showed Bloodborne and made a big deal about it not long ago to the western market - a title that appeals to a fringe base. Now I can rationalize that Sony was perhaps at the time thirsty for an exclusive to appease the hardcore crowd as games just weren't ready but....that's just one reason.
Take Gravity Rush, a game with more global appeal if marketed properly. I don't make the decisions but some of them business wise just don't make any sense. The teams still chose to release trailers for all of them - meaning they were ready to show shit and wanted part of the pie.
Well, there's a couple of reasons for not showing those games at E3.
Most of them already have a bunch of trailers out. E3 for Sony was showcasing brand new games we didn't know about sans TLG, and that got screentime only because of the date. GR2 already got a trailer, an HD release of the previous game (which Sony touted quite a bit beforehand), and hands on impressions for people to play. With a limited amount of time, why waste it on games people already saw?
Secondly, nobody wants their games buried in the wake of E3. That's why you get trailers before and after. Most people aren't even going to remember GR2 after Norman holds a baby naked.
Thirdly, and this goes into my first point I guess, showing games that we've already saw would ellict lots of bellyaching. "Oh, does Sony not have new games to show us?" Nobody wants to hear that shit ad infinitum.
Lastly, TGS, PSX, and Paris are global events still watched by people all over the world. That's why you have translators for TGS, and IIRC, Yakuza 0 (or was it Kiwami?) was announced for a global release there.
Marketing isn't just E3. There's a lot of shit that goes into it. Like, Sony was promoting the Nioh beta all over their social media networks and their youtube. They even had a blog post about it.
http://blog.us.playstation.com/tag/nioh/
So, including the fact that people have already experience the game with the alpha/will do so again with a beta, it doesn't make sense to start throwing it up centerstage for the reasons above. Both TK and Sony were smart to not do that, and the same applies to their other games.