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The signs and leaks point to a 2020 iMac release date that could happen at any time.
Jon Prosser says that the 2020 iMac is ready to go, Apple just needs to announce the new model and put it up for sale.
This is how the company delivered the iPhone SE 2 and the 2020 MacBook Pro 13.
If you need to upgrade, it's a good idea to wait through June if you don't need a 23-inch model.
The signs point to some kind of new iMac coming soon.