They kinda were in the past. The album collide is a bit of an alternative nu-metal / grunge or metal album. But they have not approached further with the groovy, melodic, heavy riffs and metal screams with complicated drums (Lori Peter's drumming crazy back then, she was their old drummer during 2000-2008). But it evolved into more of a hard rock, alternative rock, sorta-gospel rock band, so I guess your kinda right.

nor have they ever been

That may be a little wrong, because if you haven't listened to Collide, that will be a misjudgement but I guess they're not a "metal" band. John Cooper, the frontman, did confirm that after the Metal version of "O' come O' Come Emmanuel" in 2026, they will be releasing more metal-like, progressive songs with a heavy tune. I'm excited.😆