This will break posts where the author intends to format the title in large letters
Even then I think this might be a good solution. This prevents users abusing this to get attention. I don't see a legitimate reason the receiver would like some titles to be larger than others
To answer the question: The professor assumes the email referred to 1900-1910 with "late 1900s". As this was normal 20 years ago (and still gets used). He then gets upset realising the age difference between him and his student was likely the main contributor to this incorrect assumption.
To ask a question back: From https://www.bucknell.edu/fac-staff/john-penniman, I read:
I would say for religious studies it should be fine. But also for other areas, why can't you use 1994 papers?