But checking the Arduino boards.txt file:
m5stack-core-esp32.name=M5Stack-Core-ESP32
m5stack-core-esp32.upload.tool=esptool_py
m5stack-core-esp32.upload.maximum_size=1310720
m5stack-core-esp32.upload.maximum_data_size=327680
m5stack-core-esp32.build.board=M5Stack_Core_ESP32
m5stack-core-esp32.build.f_cpu=240000000L
m5stack-core-esp32.build.flash_size=4MB

4MB!

My question then is..... Am I able to upload a program to my Core-Grey that shows available Flash memory that WON'T be effected by what Arduino thinks it should be? My concern is that these details here will effect what the functions report after the sketch is uploaded, and I'll never see 16MB if it's there.

( C:\Users[--user--]\ AppData\Local\ Arduino15\packages\ esp32\hardware\esp32\ 1.0.6\boards.txt )

My plan is to tweak the boards.txt file to match the Core2 if I find the board has 16MB flash.

It's a pity that the M5Stack new revision with 16MB flash doesn't report itself as a slightly different version, so IDE's like Arduino can see them!