I'm a contributor to AMP and also work on Google Search. We're currently investigating the issue of the blank page that's mentioned in the article. So far we've been able to reproduce the issue using the Chrome emulator; however, we haven't been able to repro on an actual device, either Android or iOS. So we'll keep digging into this.
The article also mentions the impact on conversion rate. We're interested to learn more details surrounding this. Blank pages loading for many users would explain a lower conversion rate but we'd like to figure out if there's any other possible cause since it doesn't currently seem like most users hit a blank page in actual usage. I'll get in touch with the article author to see if there's openness to digging in further.