You could shift the focus from being funny to changing the meaning.
For example, in your example in the other thread, the birth date was scribed as later than the death date. Unlike common typos like "an"/"a" or "it"/"if", this typographical error changes the meaning of what is being communicated. This reminds me the "church bulletin" email memes that continuously go around. Some people find those funny but they're an example of how a typo can change the meaning of the statement.
Like:
The rosebud on the alter this morning is to announce the birth of David Alan Belzer, the sin of Rev. and Mrs. Julius Belzer.
This focus removes the subjective necessity of them being "funny" but also gives a category for the things that I believe you're trying to find a category for.
Just an idea.