The basics of executing a proper will have not changed very much over time. To be certain that a will is valid, it must be a written document. It must be signed by the testator in front of witnesses, who also must sign the will. The original and not a copy of the signed will must be presented to the court at the appropriate time.
These rules were developed because when a will is presented to the court, the deceased cannot come forward and testify that the will is valid. The witnesses can testify that they did see the deceased sign the will, while he or she was competent and not under any duress.
Most writing is now done digitally, and many people would also like to make wills digital. That presents some challenges, as the New York Law Journal explains in "Wills in the Digital Age."
The first thing that must be figured out, is what counts as a digital signature for the purposes of a will. Digital signatures are allowed for things like contracts and taxes. However, the signer of those documents can be asked if anyone needs to question whether the signature is valid.
That is not possible for a will, so it is likely that witnesses are still necessary. That leads to the question as to what constitutes witnessing a digital signature. If signing is the click of a button, must the witnesses just be present to see the button clicked?
Finally, it will need to be determined how the digital wills should be stored to make sure they are not edited after the fact.
Because of those difficulties, the introduction of digital wills is likely to be uneven in the different states. The states will most likely have different answers for the challenges presented by digital wills.
Reference: New York Law Journal (March 6, 2018) "Wills in the Digital Age."