ON/OFF push button circuit with battery under voltage protection
That is what "D" input on SN74LVC1G175 is for. In application note it always transfers Vcc ("1") to the output. If you feed it the state of voltage detector you will essentially transfer battery state to the output (although you need inverted detection signal from the one of LMS33460)

As a side note, I don't see a reason for not using something like STM6601 which does everything you want and more in one tiny package.