That could be true. We must also remember that we have PSX in December and E3 coming up next year. Sony is going to top the year off with an unveiling for sure. Theres more gameplay that needs to be seen for a their games. I can understand your reservation though.
its not a pre rendered CGI but inengine footage. they did the same with SS, techinically this is the third outing on this engine for Sucker Punch , so a 2018 release could be possible for a new IP with 4 years of development as i remember two years back yoshida mentioned that he already had played sucker punch new game, also i have no doubt in SP ability to deliver on gameplay mechanics and open world.. IMO they are by far the best sony studio in terms of gameplay mechanics even better than ND and GG.
But it remains to be seen how 2018 pans out if it gets too crowded sony will push to game in early 2019 to evenly spread out the games for that year
god of war
ni no kuni 2
and bunch of Cool looking VR titles
ghost of tsushima
The last of US 2
another iteration of GTSports
death Stranding (highly unlikely)