The exact date of release is April 8th 2022, not much more is known about the sequel yet although I guess we will get drip fed information until the release date.
Its no surprise they are releasing a sequel, the first film made $375 Million globally, and as they are sharing profit for the movie franchise with Disney this keeps their hand in the Spider-universe.
They also have their Spider-villain franchise going with Venom for which their is a sequel due next year.
There was a rumour that Tom Holland would be in the Spider-Verse sequel as the real life Spider-Man who gets sucked into the animated world, that would be fun if true.
April 8, 2022 ? #SpiderVerse pic.twitter.com/FC5nVIuciB
— Spider-Man: Into The Spider-Verse (@SpiderVerse) November 1, 2019