Beyond the "decency/good taste" issues, the validity of which I accept, I think the biggest problem regarding "too soon..." is the possibility [probability?] of later information changing the particulars in a major way - the obvious example is perhaps that of a murder case being resolved with the percieved guilt of the individual who was tried for the crime ; this individual then being pardoned because the conviction was found to be totally incorrect.
[Not much help if the death penalty is carried out, of course, as it is in some countries...]
This means the details of the work are not based on the exact truth, and may be completely incorrect - but if the work is fiction,or "based on" [ grrrr...
] it may not matter. [Basementary ?]