now that delay would only be needed if you want to write to the arduino
at the beginning of your program.
for usual operation the serial event will tell you when some data FROM arduino have arrived, so it is not needed in that case.
the arduinos what reset at serial connection ( not all do that (Leonardo) ) also reset at
at end of communication, a mostly unknown thing, but if you want to setup a arduino
by some initial serial commands and then let it run alone ( disconnect )
that will fail unless you write all settings ( changes) to eeprom ( and read from it at boot ).