Several shady propaganda accounts that were involved in promoting various Israeli government deceptions (40 beheaded babies lie and others) are claiming the bodies of 21 Israeli hostages were found by Israeli forces in Khan Yunis, and that they were killed by Hamas. They present zero evidence of these explosives claims.
I haven't seen this reported in Israeli or foreign news sources, and a family member of a hostage who I just spoke to hasn't heard about this either.
Wait and see, but note that disinformation operatives are the apparent origin of this claim.
Mike