The lack of context is a general problem for communication. If you don't give sufficient context, you might cause anxiety, like in this case, but this is not the only problem. If you lack context your message will often not be understood.
E.g. I was asked if I remember Nick. I didn't know who Nick was, there are many Nicks in the world. I might be bad with names in any case. Then I inquired about some context, I was told it's Anna's friend. I don't know who Anna is either, also a very common name. After a bit of back and forth I find out it's a guy I talked to at a wedding last month. There were hundreds of new names for me. Names I would probably not remember. But if you start with "do you remember Nick, the guy at the wedding we talked to about X", I might stand a chance.
100% this.
Not just in the workplace, but in all human interaction. If people don't know what's happening, they'll fill in the blanks on their own -- and usually they'll fill them in with a worst-case scenario.
If you don't give context, chances are they'll fill in their own.