Couple of his hits as a producer he probably talking about:

Not a big deal

FL tells you in you're in key or not for the rest of your project from your first melody you start, or you can present a key to stay in and it'll highlight your spots on the piano roll

Structure, sound design/selection & rhythm is the most important nowadays

Also the beat doesn't just end with him, there's an engineer behind him that will also clean stuff up

There are plenty of people that can play instruments or know music theory but don't know how to make a song, concept or feeling to save their life

It all depends, but this isn't anything too crazy in today's era - he is also still talented

facts

i barely know music theory also

Yeah once that I heard that artists like Hendrix, The Beatles, etc didn't know much theory I kind of got the impression that it isn't necessary to make great music.

With that being said it's still probably better to learn some of it, simply because it's better to have as a tool than not. Honestly I feel like the level of theory you need make electronic music isn't much. You can learn all the basics in a single afternoon. Once you get to more advanced stuff like reading music you can pretty much ignore it if you want to.