No, it does not sound in the best interest of the 5 other siblings.  First, a Will must be written in Minnesota.  Oral Wills are not valid.  Also, it sounds as if the sibling was given a life estate but again, it has to be in writing in a Will.  If your Mother in Law dies intestate - with out a Will - then the children will share equally and each have equal rights right now.  Now, if the kids want to agree to let the brother live in the house that is their choice but I would speak with a different lawyer asap.  Not his lawyer.  No agreement should be made between them unless it is in writing and signed by all of them.  A party needs to be appointed as the Administrator to evict the other brother.  Good luck.