Musar על סנהדרין 218:14

When the Talmud in Sanhedrin 108, debates whether Korach and family will be resurrected when the time comes, the expression עדת קרח used there does not include these two hundred and fifty men. They will certainly qualify for resurrection, seeing theirs had been a noble intention. We can deduce this also from the wording in the Mishnah there which reads: עדת קרח אינה עתידה לעלות, which is proven from the verse: ותכס עליהם הארץ, "the earth covered them," an expression of finality (which clearly refers only to those who were swallowed by the earth).