That's for basic testing. The post also says they still keep a long tail set of devices for more comprehensive testing.
"We figured out the optimal combination of devices to give us maximum coverage. We are able to reduce our daily smoke automation devices to around 10 phones and 4 tablets and keep the rest for the longer release wide test cycles."
Is it 400 devices? Or are you assuming that to justify your post?
"This was not meant to be a warning for devs to stay away of Android, but doing more extensive QA testing is a reality of the platform."
Your headline & picture suggest otherwise.
Honestly, is this a Techcrunch thing? Before you worked at Techcrunch, I can't remember you writing a post like this. Too much snark and mocking a platform (and hence, a community).
"We figured out the optimal combination of devices to give us maximum coverage. We are able to reduce our daily smoke automation devices to around 10 phones and 4 tablets and keep the rest for the longer release wide test cycles."