The ESA refuted that the 2021 event will be behind a paywall.
The Entertainment Software Association (ESA) denied the rumors that the E3 2021 will be a Pay-2-Attend event. They did not, however, denied that some of the features of the upcoming event might be chargeable.
It is yet unknown, what parts of the digital game event will not be accessible for free, but VGS reports that "The ESA has discussed bundling some parts of its consumer offering as part of a paid access pass, which could be for the on-demand game demos or a ‘premium’ package with extra access."
We must remind you that the ESA previously confirmed that E3 2021 would be a digital event, due to the COVID-19 pandemic. Because of that, many game publishers decided to hold their own events during the summer of 2021.