Their marketing this gen has been absolutely spot on with a few exepexcept like GT Sport. Announcing early has worked for Uncharted, horizon, Spiderman and GoW. And will most likely continue to work for their other big games. I agree with you that it has been a successThe thing is that, while yes development time or at least the human capital necessary to make AAA games is going to continue to increase into next gen, Sony has imo actually smartly taken their position of dominance this gen, to lay the foundation for quicker game development for their games going into next gen. They are putting the time and money, that they are afforded by their current situation, into creating great and popular first entries of game series, that can they can then more efficiently create sequels for in the coming generation.
However with development time increasing rapidly for Sony first part titles, it seems they are having trouble with shows late in the gen. And now it seems most of their studios are shifting their work to PS5. Or finishing up their current games
What does bother me a bit is that they aren't working with third parties a lot to show off stuff on their show. To me that's always been an important part of E3 and their show cases.
MS will most likely have a good E3, maybe Nintendo too, but it will be interesting to see what happens.
Sequels to Horizon, God of War (not technically a new IP, but still a huge departure from the series to date), Days Gone, Dreams, Ghost of Tsushima, maybe even Spider-Man (even though Insomniac are already an insanely effiecient studio, if you think about it) or Death Stranding should be a lot easier and quicker to make as the basics for these franchises are established at that point. I mean we already have comments by Hermen Hulst stating that GG wants to be able to release a game every 2-3 years going forward or by Polyphony Digital that their models are being created with the future in mind.
It might seem counter intuitive, but my personaly theory, and this might be completely disproven by Sony next gen, is that in terms of first party this generation has been one of putting in the hard work, to then "reap the results" in the next gen. A generation of properly putting their first party on the gaming map so to speak (outside of Japan Studios unfortunately).
As such I'm personally expecting a lot less in terms of new IP next gen from Sony. Probably something from ND, maybe SSM will get another shot, Japan Studios, QD if they decide to continue working with them, apparently Bend might be working on one but I kinda doubt that's going to come to fruition (or it'll be something smaller), but other than that I expect a lot of sequels to successful PS4 exclusives on PS5.