I was just talking with people at lunch several weeks ago about this, before the violence.
General agreement, at least with the locals I have been speaking with (and there will be a lot more) is this is an example of a monument (not a statue) that should stay. It is nothing more than a historical marker on a historical property saying that the old fort was used as a prison during the civil war, and soldiers died there.
The fact that the mayor is thinking of removing it is overboard and over the top, and purely political.
I am not all for monuments honoring the confederacy, but this is an example of one that does have historical significance in it brought the harsh reality of the conflict to Boston's doorstep, and should be noted. It also was not paid for or placed with government funds. If you want to replace it because you don't like who put it there, then the taxpayer should replace it with a stone and the original should be put inside or in a museum. Or if feel that strongly you should make a donation as, I am sure the park service will gladly take your money for its replacement.
That is all.