At this point it's just pure meaningless sales-talk IMO, of course they say there are no plans for GT7 because they want to sell GT:S as much as possible and have all the media and possible buyers focused on that one. GT:S is very different from what the GT series have been, I can perfectly understand people who enjoy a fully fledged career more, a decent amount of tracks, a bunch of classic cars not being happy about it, that is yours truly included. But it is what it is, you can either accept it and give it a try, or abandon it and move on to something similar. There are plenty of games out there from the most arcade towards the most sim and everything in between.
In a way I already left GT for Forza in 2015 when Turn 10 was touting FM6 with a lot of shiny video trailers while I was sitting there with my aging PS3 (with GT5 & GT6 on it) and no news whatsoever from PD. So I bought an XBox One and moved on, never really looked back to GT6 to be honest.
Fast forward to today I have a PS4 Pro as well now though, bought that one earlier this year for the PS exclusive titles like Horizon Zero Dawn, the Uncharted and Last of Us remastered series and whatever the future might bring. My entire home cinema system is even 4K HDR ready, GT:S is within my grasp, money isn't even an issue (time most definitely is) but I am just not nearly as interested in it as I was back in the days with GT5 or GT6. I preordered PCARS 2 as that will be my main game from september on but I'll keep an eye out on how GT:S evolves. There are still some things of old which I liked that are partly present in GT:S as well, like the manufacturer background info, the way PD does fictional tracks like noone else does and even the very simple things like the click sounds in the menus.
But there is a lot in GT:S which I don't like either: no classic cars, barely any real world tracks, fictional Vision GT cars, fictional spec group B cars and for someone who only races in cockpit view that awkward positioning of the hands on the wheel with the wrists pointing unnaturally deep to the inside really turns me off as well. Photo mode seems to have gotten a lot of attention as well in this title but that's something that don't interest me at all (in any game). If I want pretty pictures of pretty cars I'll just Google them, easy as that. Sound on the other hand seems improved a lot over GT6 but it's still not near the likes of AC or PCARS.
The game also really needs to have a proper singleplayer campaign to begin with, if PD plans to patch that in via DLC or expansion pack content in the future then they have my interest. If not... well I will follow how everything evolves after release and then decide what to do. But I'm not jumping aboard on promises, rumors, plans or anything like that. Only facts for this title and facts for me are post-release reviews and available DLC (not planned DLC since we all know how long we had to wait for B-spec or heck even the track creator in GT6).
Either way I still fail to understand the direction PD is heading with this one. So they drop their entire singleplayer fanbase to jump onto this eSports bandwagon. Then they start adding the scapes mode to attract some lost singleplayers again I think? And the Vision GT program... IMO it doesn't even have a place in eSports to begin with, fictional futuristic cars screams singleplayer all over it, eSports should focus on the race cars of the modern days like GT, touring and prototypes. If I would see a live broadcast of Vision GT 2025+ cars racing in nerfed/fabricated/BOP'ed/fictional/whatever specs just so they match with 2016-ish LMP1 cars and then have that mixed bag of nothing race around the Nordschleife I would have a good laugh. You might as well call Need for Speed 2015 a more realistic game since they do focus on street cars racing on streets, no matter how arcade that game is, it's a game that still makes sense. GT:S for me honestly makes no sense. I really try to understand how FIA license, lack of tracks, Vision GT, eSports, no singleplayer, scapes modes, manucaturer history, no classic cars, no singleplayer all fits together in the same game because I simply do not understand these design decisions at all.
Still, like I said, I will keep an eye on how it all evolves and if parts of the game turn out to be fun and it gets good reviews and people play it enthousiastic on streams then I might get it as well.