If they want, they can announce all the exclusives and big AAA games they have for the rest of the generation in a single event because they are under development, or even to make al least a CG teaser of games that still aren't under development, as MS did.
But this is a bad idea for several reasons:
- They would run out of big announcements for the rest of the generation, so people would complain even more than now about the lack of big announcements
- In terms of marketing it's better for them to spread their hype bullets around the years, and inside a year across different events combined with short term lower tier games instead of focusing all in a single event
- They are now with record hardware, software and subscription sales, don't need to pump the hype now, they can wait and focus instead on marketing know PSVR2 and that PS5 consoles are in stock
- To focus the hype on games that will be released in the short term, let's say to be released on the next 6 to 12 months helps giving extra attention and sales to more games: not only top tier ones: smaller 1st party ones like VR ones, indies or 3rd party AA/AAA with marketing deal or temporal console exclusivity. These games would sell less if Sony focuses instead on long term games
- To announce games too early set some expectations in terms of visuals showing a vertical slice that in many cases for many reasons later the final games can't achive on retail consoles. It's better to wait to show the games when almost completed, around a year or less before its release
- To announce release dates too early is a bad idea because players and investors realize that games get delayed so often and is a bad pr move and puts too much pressure on devs. It's better to wait to announce release date once it's on beta and they basicallly only have to do tweaks, bugfixing, PR and marketing
- Sony's current strategy of focusing on marketing short term games it's the best performing one for the console makers. Nintendo and Sony are breaking records with this strategy. So wouldn't make sense to change it a lot
- Sony has been (and will continue) growing their internal teams, acquiring new ones and signing more 3rd party deals than ever before. Meaning, the amount of big releases for the short term will keep increasing. Meaning that they'll need to market more short term releases and will have less space to market long term releases
So yes, they may make an exception and make a show announcing their big games for the next 3 years or beyond, but I think it won't happen. I think they'll focus on announcing and showing their games for the next year or year and a half, so 2023 and (mostly H1) 2024 games with maybe only one or two exceptions that would be pretty likely H1 2025 games.