Admins?
I also agree: these keys are named using prefixes for powers of ten, so the abbreviated formats should also use power of tens (without any "i"). If some project decides to use powers of two, they'll need to use other message keys ("Size-kibibytes" and so on) and associated keys for abbreviated formats ("$1 kiB") will be needed as well and translated separately. There's certainly a problem in projects that use these units, without being entirely clear (when in fact they shuold have use the other units).
But isolately, on these messages used independantly of a clear scope, we cannot change anything here. It's up to projects using these messages to update their code to reference the correct units.
Anyway, I added a "Related" template in the doc to link these messages and present them in a table (showing powers of 2 for memory or file sizes, and powers of 10 for bit rates). This allows poiting to these messages and update them consistantly. I tried to see if there were messages naming sizes in "kibibytes" or "kibibits" for powers of 2, but did not find any of them.