I think you’re confusing the hardware reset button, which is always connected to EN or RST on MCUs with the button that is used to reset the Blynk dynamically provisioned credentials.
Not everyone uses the Arduino IDE, and the whole point of this is to allow the user to define different LEDs and reset buttons if required. ALso, as you’ll see from the other board definitions, some use RGB LEDs and the LED_BUILTIN option won’t work with these.
Anyone who is having issues like this should probably read this…
Pete.