Both for them and for us is better to have a recorded video than to make a live reveal: avoid consoles crashing, people speaking in a weird way, cameras not focusing in what is important, awkard executives who don't know how to talk in public or don't speak English properly, the video quality would be better, etc.
I think they should made a great 1 hour long State of Play video just to reveal the console:
-Video of a family playing the console while they explain the concept behind the console and its main features (improved and refocused PS Now, Remote Play, Cross Buy, Cross Play, Cross Save, Backward Compatibility...)
-3D version of the console and the pad rotating and explaining its buttons, ports and features focusing on new things (100GB Bluray, haptic feedback, adaptative triggers, etc)
-Some words from Cerny talking about its hardware architecture and explaining its main technical specs and innovations (raytracing, streaming and backwards compatibility focused hardware, etc)
-Hermen Hulst announce optional free improvements for BC games, in the same way they did work in PS4 Pro and show a PS4 vs PS5 comparision of some PlayStation Worldwide Studios, probably Horizon.
-Then they announce and show 4 Sony games: Horizon 2, Spiderman 2, and the Bluepoint game, maybe with some folk mentioning how powerful is the console and highlighting some things they couldn't do before.
-Some words from some Capcom/Ubisoft/Square activision guys mentioning that the console is super powerful and easy to develop, and show some tech demos/WIP games that highlight some extra things they now can do with that hardware thanks to the extra horsepower, RT and super fast SSD.
-Some words from Shu Yoshida to explain how easy it's going to be for indies to develop for it and how BC is going to help them (an indie can release a PS4 to take advantage of the 100M installbase and people can buy it on PS5, maybe with optional improvements)
-They don't announce a date or price, and ask devs to attend GDC to listen their talks about how enhace BC games, how to take advantage of RT, etc.
-Hey, we have one more thing... Mark Cerny appaears again to showcase Knack 3: Shadow of the Last Knack Guardian, the launch game from Japan Studio.
It doesn't matter how they're gonna announce it, when the journos pick it up, it's gonna explode all over the internet.
State of Play has ZERO pomp and circumstance.
With State of Play instead of E3, PS4 sold more games during 2019 than any other console in a single year. Only there is another case where a console sold more games in a single year: PS4 in 2018.
Their Instagram post with the PS5 logo is the most liked Instagram post ever from an official game / gaming company account.
Their own channels are more powerful than the journos channels. And well, the journos also con write after watching the same video than us. There is no reason for them to send journos to an event where journos won't be able to play games and very likely won't be able to interview people.
The format also works really well for Nintendo with Nintendo Direct and similar streams: with streamings instead of presential events they avoid the filter of the media making sure the fans receive the message how they wanted, they control the message. And then, the media who wants write about it.
