Overwatch 1 servers will go down on October 2; Overwatch 2 servers go live on October 4
Blizzard confirmed yesterday in a roundtable interview that October 2 will be the last day users are able to play the original Overwatch that released in 2016. The servers will shut down sometime on October 2 (if you're in the Pacific timezone; no specific time was mentioned, so it may be October 3 depending on your timezone), and roughly 27 hours later the Overwatch 2 servers will go up, at which point it will be the only Overwatch experience in operation.
"We'll give current Overwatch players the ability to download Overwatch 2 a little bit ahead of when we launch, if they want to pre-download," said commercial lead Jon Spector. "We'll share a kind of launch checklist with players ahead of things so that they have a smooth experience getting in on 4th October, when we launch."
Overwatch 2 will be free-to-play, so old players won't need to pay again to upgrade to the new version, but the experience will undoubtedly be different in a free-to-play game. Reportedly, loot boxes will be a thing of the past, and will be replaced by a Battle Pass, with both a free and a premium version. There will also be an item shop where players can spend a premium currency to buy items directly. (More information on Overwatch 2's monetization can be found in Eurogamer's very detailed breakdown here.)
This release comes at the end of a somewhat troubled development cycle for Overwatch 2. Originally announced in 2019, it was expected to exist alongside the original, offering an alternate entry point into a shared multiplayer space rather than replacing the first Overwatch. Development continued quietly until last year when, in the months following the Activision Blizzard's legal troubles, its director and head developer both exited the company with more than a year remaining before release.