I imagine it’s mostly up to interpretation. We have very few notable cinematic representations of the capabilities of the seemingly more mundane classes. Among the examples I can recall Warriors haven’t been shown to be inherently magical; then there’s that trailer in BfA featuring Rogues…
I personally go by the following; these classes aren’t magical at their base but iterations of them can be. Abilities of these classes that may appear magical in-game can often be interpreted in different ways.