According to this obituary Stewart Cheifet of Computer Chronicles passed away on December 28, 2025. The only other mentions I found online link to that obituary. Wikipedia, which is usually quite timely in updating the entries of persons who passed away, three days later still lists only the birth date.
Are there independent and trusted confirmations?
The Wikipedia entry has just added the date of death citing the same Goldsteins’ Fineral Director source.
S.M. Oliva of Computer Chronicles Revisited on Stewart Cheifet:
I felt compelled to write up my feelings about the impact his work made on me. This is unrelated to Stone Tools, except that I had just referenced him in the HyperCard post so he was already on my mind recently.