1. Translation of frequency spectrum into notational values
I'll assume that this is a contrived of saying that it's useful in acquiring a good sense of pitch. Piano playing has what to do with this? Couldn't you do this with many other instruments? I think fretless string instruments are superior in this regard.
2. Ease of communication with musicians in the workplace
How about taking courses in music theory, or, again, whatever instrument you prefer? Even if I positively need to show a chord or two to a keyboard player, it's no big deal without specifically taking a piano course.
3. For a recording engineer, ability to sequence digital parts by ear on a piano keyboard
"Sequence digital parts by ear?" You mean, like, putting notes in a piano roll according to what you have in mind? Yes, you totally need to know how to play piano to do that, because the kind of layout where notes are layed out linearly in a bunch of rows from low to high wouldn't really make sense to any other musician...
I could come up with more, but suffice it to say, I doubt you will find a school with a music technology degree that doesn't force some kind of music theory and/or basic piano.
While this might be true, I don't really see how it supports what you said.