I have a lot of complicated thoughts on this one.
E3 2019 wasn't the last E3, I believe E3 will go on for a few more years still. But E3 was already on its way out the door and growing in irrelevancy before this, I think this year being skipped (and it being a kinda' important year as it's a next-gen coming up year) is going to greatly speed up the process. Unless the ESA do something to turn this ship around, while E3 won't be dead I imagine it'll just continue to be a much smaller event not nearly as big as previous years, just accelerated now.
Obviously E3 not being around this year doesn't mean we're not getting gaming announcements, but it'll be interesting to see how publishers scramble to get their announcements in front of as many eyes as possible. I think most big publishers will be fine, but I actually can see this hurting a lot of smaller developers and press sites. E3 is one of the greatest windows for small developers to get their games highlighted and more public attention, and often there's a summer bump in revenue for gaming news sites. With E3 not being here this year and everything more spread out, I can see this seriously affecting some places and I won't even be surprised if it leads to some studio closures in the long-term.
E3 demos take a lot of time and money to make, and for certain some studios have been prepping E3 demos for a while now, so I'm curious if they'll be able to find another way to distribute these demos or not. I could see this being a sunk cost of time and money for many as you often have to prepare these demos way ahead of time, or Hell prepare other things as well that now have no use.
It still was 100% the right call to make. I think it's good the Coronavirus is being taken seriously, even if there's a bit of fear mongering about it, it's better it's taken very seriously and the health of people considered first. The other things suck but I don't think this was the wrong call.
I honestly do think this might be the end of an era, E3 won't be dead but unless ESA really pull something off I don't think it's going to return in the same form again as it has been. I know E3 has some big problems and had some big fuck-ups in recent years, but what this also means if E3 does grow in irrelevancy is that the US doesn't have a major video game conference event, which think is a detriment to the industry I believe. I agree Streams and Directs and such will catch on more, and that is a good thing in its own ways, but the US missing out on a big singular conference event for gaming I think has some major cons for the industry. E3 was a great chance for people to make industry connections, for lots of meet and greets, and a good place for lots of meetings, press events, for smaller-medium devs to have a chance to get their game out there, and if E3 does slowly grow irrelevant I do think that is at a huge cost to the industry as a whole.
I do expect between this and other things we're looking at the gaming industry having some major changes within the next decade though.