Why are different names given to the same bit in MPLAB XC8?
I would like to respond to your question as why Microchip has multiple names for bits in some of the Special Function Register.

I have been using Microchip controller since the PIC16C54 was introduced, or about 25 years. At first the documentation was written by engineers and they were not too concerned about consistency with naming registers or bits.

The result is that there is a legacy code base that uses variant names. To allow that code to build when Microchip updated the assemblers or compilers aliases were injected for variant names of registers and bits. I doubt that the names were added just to make C code more readable.

I admit that this is opinion based on years of observation and not on any statements from Microchip.

Should anyone have direct knowledge I, for one, would appreciate being told I am wrong.