If your separation agreement states that you have to pay child support, you have to pay child support, regardless of where the child is living or where they move to. Regardless of whether your wife plans to remarry, the child is still a child and will need your support. Her marital status has nothing to do with your child support obligations.
If you are getting divorced in Massachusetts, and have agreed to pay child support you must continue to pay child support. The only way you can get out of paying child support is via court order. The only way you can actually STOP paying child support is if you give up your parental rights - and even then sometimes the court will order you to pay.
The question is whether you agree to the removal. This is something that you should deal with an attorney. Having said nothing about his removal, the next question is hard to answer. However, if there is an order, then you have to continue to obey the order.