Surely they aren't releasing a new, incompatible version and expecting us to pretend it's the same format...?
> This updates the existing image/png Internet Media type
whyyyyyyy
We went to pretty extreme lengths to make sure old software worked with the new changes. Effectively, the limit will be the software, not the image.
For example, you can imagine some old software that is unaware of color spaces and treats everything as sRGB. There is nothing we can do to make that software show a Display P3 correctly. However, we can still show the image well enough that a user understands "that is a red apple".