This really has nothing to do with WN. Hopefully a Mod will be along to move this to New England where there is extensive discussion and information. To be clear, in order to avoid quarantine one must have a pre-arrival negative test (see link below for the governor's order and explanatory information). If you wait until arrival for the test, you are in quarantine until your test arrives. The rapid test only takes 15 minutes, but has a high false positive rate. If you rapid test positive, they then run a standard test and that takes 2-3 days to come back, during which time you would be isolated.
Also seems a bad idea for anyone to travel without a test. If you are positive, you presumably want to be treated at home. As this is work-related, I would also presume that an employer does not want the risk and liability associated with sending those shedding the virus
https://www.mass.gov/info-details/covid-19-travel-order