I love Calvin Harris but his music is not that much EDM anymore, he is making pure pop and Soul. Zedd was great when he was doing Dubstep remixes. That's why they call him EDM. But not that much anymore. David Guetta is the same story with Calvin Harris. But some of his music is still pure EDM. If you take a look at this playlist you can hear the difference between EDM and Pop. Not all DJ's always makes EDM.
If it's pop, it can't be EDM? Doesn't make sense. If it's house it can't be EDM too? You can't create a specific brand of EDM. It's an umbrella term for multiple genre ie: techno, house, bass, dubstep, trap and its sub genres.