While the ESA originally kept saying they'd possibly bring E3 back, as of December 2023 they've now stated that the event is officially cancelled for good. The last regular E3 was 2019, just before the COVID pandemic, and while the ESA did hold a digital-only version of E3 in 2021, plans to bring E3 back as an in-person event following the availability of the COVID vaccine were still cancelled.
Looks like from now on the main video gaming summer event with be Geoff Keighley's "Summer Games Fest," and companies like Nintendo will just stick to their usual "do one big Direct at some point in the summer."
I know opinions on E3 in the last couple of years of its life were mixed at best, but it does still suck to know a major gaming staple for roughly 25 years is now coming to an end.