Not at all! Heavy Metal music is a big deal over there; Jokowi is a big death metal fan. Metal music was closely tied to the transition to democracy in the late 90s. Since hardcore is a subtype of metal music, this makes sense.
....
This is: 1-not true and 2-REALLY not something you ever want to say to a serious fan of hardcore or metalhead.
You don't see any death or black metal band shirts at Furnace Fest and most metalheads wouldn't be caught dead in a Knocked Loose or Misery Signals shirt. Similarly hardcore fans love emo, and it's pretty obvious what metal fans think of it.
But regardless, I did know of hardcore bands in Indonesia previously. It's the Christian part that's surprising.
On a side note the lack of real metal bands at Furnace Fest has led to a pretty hilarious meme ongoing in the community now with the "Extol guy", who'll no doubt still be joked about until the 2024 fest.