If I buy a used or refurbished (not from Apple) watch, is it possible the O2 sensor would still be enabled?

If I buy a used or refurbished (not from Apple) watch, is it possible the O2 sensor would still be enabled? In other words, if the hardware has not gone through apple for refurbishing, will resetting the watch to a new owner bring in a software update that would turn off the O2 sensor capability or would it remain? Thanks!