To me, if GT7 does not show up at TGS, it seems more likely to be at PGW as the series does extremely well in the European market.
The big (new reveal) game at PSX is likely going be God of War 4.
@ PSX
Revealing both GT7 & GOW 4/Mythology Reboot at PSX would make it a pretty memorable event. I guess it could be at PGW, though you'd think they would focus on European made games there as well as some of the games close to release.
For Sony, I'm predicting...
TGS
Gravity Rush 2 (& 1 PS4 version)
Hot Shot Golf/Everybody's Golf PS4
The Last Guardian
Bloodborne DLC reveal
Possible new big internally developed 1st party announcement (JRPG? some kind of action adventure?)
Maybe a new collaboration like Bloodborne (Level-5 JRPG?)
+ some smaller & already announced titles
PGW
Horizon
Dreams proper reveal
Wild proper reveal
Rime
Quantic Dream's announcement
+ smaller titles like Alienation etc.
+ some non-European games like Uncharted that are getting pretty close to release
PSX
GT7
GOW4
FFVII Remake new title reveal, possible first footage
Some big 3rd party announcement like last year
+ lots of stuff from already announced games