Would you like these changes in Bitcoin Core?
[1] Replace "µBTC" with "µBit",
[2] replace "mBTC" with "mBit", and
[3] switch to "µBit" as the default unit.
Your question is not clear for me.
Do you also mean that µBTC == µBit?
Yes.
The only difference between µBTC and µBit is that "µBTC" is the current word, and "µBit" is the proposed new word.
See above.