There are differences--you're often willing to do more work decoding a still than a frame, say--and in the first story I linked there's a quote from a Googler wondering about whether to make the image format exactly track AV1 or to tweak it. So, there's a real question.
That said, the still demo at https://people.xiph.org/~tdaede/av1stilldemo/ is really encouraging, and Apple's seen a win in doing something parallel with HEVC/.heic. AV1's already gone through a lot of optimization and IP vetting (patents caused trouble for previously proposed replacements for JPEG), and has a hardware decoder design and a lot of companies signed on. Like everyone I just have to wait and see what they do, but I'm more or less on team "ship it" here.
That said, the still demo at https://people.xiph.org/~tdaede/av1stilldemo/ is really encouraging, and Apple's seen a win in doing something parallel with HEVC/.heic. AV1's already gone through a lot of optimization and IP vetting (patents caused trouble for previously proposed replacements for JPEG), and has a hardware decoder design and a lot of companies signed on. Like everyone I just have to wait and see what they do, but I'm more or less on team "ship it" here.