I never played Mother 3, but I do know what happens to Claus, so yeah. Also Chara just died from an illness, it's not that tragic, but Asriel dying because the humans thinking he killed Chara, so they killed him. That one is tragic.
Also I don't think Kris will die, I think that shirt is a hand-me-down from Asriel. Remember, Deltarune is a timeline where the war never happened, so Asriel didn't die, making him older (the game even says he's in college).