I hadn't heard of this, but something similar has been attested with Thai:
"Two of the consonants, ฃ (kho khuat) and ฅ (kho khon), are no longer used in written Thai, but still appear on many keyboards and in character sets. When the first Thai typewriter was developed by Edwin Hunter McFarland in 1892, there was simply no space for all characters, thus two had to be left out."
(source https://en.wikipedia.org/wiki/Thai_script , pointing to https://web.archive.org/web/20101219214315/http://www.t-h-a-... )