the skeleton is key

At work we had a minor question about the use of skeleton placeholders. If you have a static form being populated, says, so the shape of the data doesn't have much impact on the final result, should you:

A. Keep as much of the form detail as possible, like keeping in textarea captions, and just replacing the inputs with appropriately sized place holders? (this might limit screen "pop" which is an age old goal for web apps.)
B. Go fully abstract, having a single block represent say a textarea with its caption above?
C. Split the difference, replacing the input field with a box but with the caption having its own box?

Looking around to guess at best practices, it seems C is a good balance: here's FB's Messenger. The short rectangle on the top line will be replaced with "Chats", the other two circles on that row are placeholders for some action icons. 

The mix of "real text" and rectangles would be a bit weird, even if one is persistent meta information, but it's nice to suggest at the general shape of what's coming down the pipe.