If you remove the population of all of greater Boston, a rather generous 5 million, then Massachusetts is still the 10th most densely populated state, beating out California, and coming in just behind Ohio.

That greater Boston metropolitan area figure may or may mot also include population from neighboring Rhode Island and Vermont, not entirely sure on that

If you just take the population of Boston proper, 675k, out of the equation, then Massachusetts maintains its spot as 3rd most dense US state, doubling the density of New York

So conclusion: Massachusetts is dense af (relative to the US) even without Boston