MIPS was in bad shape when Imagination acquired them. Then, not long after, Imagination's GPU business was starting to go downhill, so they couldn't focus as much as they may have wanted on MIPS CPUs. Also MIPS failed to gain traction with Android, just as x86 did. And then Apple dumped Imagination's GPUs, which was basically a death sentence for the company, so they had to get rid of MIPS.

Wave looks like a pretty cool startup, but I'm not sure how helpful MIPS architecture would be to them. The biggest benefit is probably not getting sued by Intel or other large players.