I am one of the people who experienced this 520/502 error, with plugin auto-updates turned on it took me the whole of 5 minutes to recognise that the Cloudflare plugin was the culprit. This is the second time that I have been burned by auto-updates and while I appreciate how responsive Cloudflare has been in solving this issue it is indicative of a common problem in the developer community.

The problem as one person once put it to me is this:
The developer has a high end mad specs laptop/computer that they use to develop with superfast internet and superfast/supercharged everything. They develop this awesome product and proceed to test it on this awesome set up without ever considering the simple fact that Joe the user has got a puny device. Developer is shocked people think their product is crap even though it's awesome on their end.

Morale of the story: Always put yourself in the user's shoes.