When I started working in the 1980s, they were still some consultants who thought it was bad to tell people they had MND (ALS) or MS, it was even not unheard of that people with end stage cancer were not told their diagnosis, the argument was that it was bad to take away people’s hope.
I remember having run ins with a couple of neurologists who argued this, saying given there was no curative treatment it was better to lie to the patient. It took a lot to get them to understand that decline could be much better managed if such as alternative feeding methods or alternative communication aids were ready in advance rather than after the fact. With MND and MS once it was realised that there are management tools people were less likely to fear the difficult conversations. We just need to get there with ME/CFS.