Case:


Ruling: There are several ways to validate this problematic will. Since it was written a month before dec’s death, when he was suffering from a severe chronic illness, one could view the will as the instructions of a shciv mei’ra (one who may die imminently), which are valid despite the language. However, since the expected imminence of his death cannot be proved, this will not help (see Shulchan Aruch, Choshen Mishpat 251:2).
There is a concept of "it is a mitzva to carry out the words of the deceased." While the Shulchan Aruch (ibid. 252:2) says that this is only when the deceased entrusted the property in question to someone for safeguarding, several authorities do not limit it. The Binyan Tzion says that if an executor, who is not an inheritor, controls the property and gives it to those named in the will, the inheritors cannot extract the money out of doubt. In this case, where the inheritors are not known and it is possible that were they to know the situation they would relinquish their rights, we should carry out the will. Regarding the shul, since a pledge to tzedaka is like the handing over of a gift, the Achiezer indicates that the case is no worse than when the property was given to someone for safeguarding.
A further reason to validate the will is that it is dated, as R. Yossi says that when the date of a document is written, the transaction begins at that point. The Rama (CM 258:1) does point out that if the date is written as a formality, it does not help, and that is generally the case nowadays. On the other hand, we should consider that dec was religious, left half his assets to a shul, and hired religious lawyers to write a will. Thus, he apparently wanted it to be halachically valid, and we should take the date seriously if that validates the document (based on Tosafot, Gittin 9a).
A further reason to accept the will is that it was written in a manner that is binding according to the law and practice of the land. While we would not validate the will if it were written in a manner that uproots the halacha of who inherits, there is a basis to validate gifts to specific people even if the correct halachic formula was not used. As Rav M. Feinstein said, if what is missing is a valid kinyan, the fact that the courts uphold it is no worse than a kinyan (we omitted many varied sources on this matter.)
Furthermore, since it seems impossible for anyone to prove that they are the halachic inheritor, the actual inheritor is like one whose property is irretrievably lost, where we say that the ownership falls off (see Bava Metzia 22b). Regarding dec’s bank account, it is likely considered a loan that the bank owes dec according to the rules of the bank, which likely includes that they give the money to those listed in a legal will.
Therefore, we approve the dispersing of the will, on condition that the recipients sign that if someone comes with the claim of inheritance they will go with him to a din Torah.