No, nobody ever says “I’m going to higher you” as a way to indicate they are promoting you. Not in the military, not in non-profits, not in the government, and not in any private or public business in the US.
“Higher” is a homophone with “hire” and “hire” already has a critical role in reference to career management.
At this point I can only assume you haven’t worked somewhere where English is the spoken language.
People say they want to move up the corporate ladder, which implies higher, and brings a visual analogy to the phrase that is compatible with what I said.
There is no adverbial expression using the radical "up". The adverbiality must come from "high".
> “Higher” is a homophone with “hire” and “hire”
This phrase doesn't make sense.
> At this point I can only assume you haven’t worked somewhere where English is the spoken language.
What you assume doesnt't matter. Where I worked or not doesn't matter.
Because English is clearly not a language you have a day to day grasp on. Read the rest of the sentence. You weren’t able to correctly split a compound sentence.
https://en.wiktionary.org/wiki/highering
I agree that it is an unusual choice, but that doesn't mean you can assume it was a mispelling.
Moreover, the meaning went through. Ultimately, the word itself does not matter, and none of your explanations are relevant.