Census data has a lag, particularly from the American Community Survey. Most municipal population numbers are based on a ACS 5-year average of the previous years posted... for example, if Revere had the following population estimates for 5 years, their 2019 population would read 53,000 (their listed population was 53,073 for 2019).
2010 - 51,755
...
2015 - 52,000
2016 - 52,500
2017 - 53,000
2018 - 53,500
2019 - 54,000
Another contribution for the lag is that new housing units are not always immediately accounted for in a given year's population estimates. This is generally rectified by the decennial census when the US Census Bureau has address canvassers go to every census tract in the country to corroborate addresses.
Until the 2020 decennial census data is released next summer, we won't have a clear picture of how many people actually live in all municipalities.