The men involved in the unrest that we call Shays' Rebellion certainly did not want Massachusetts to default.
Their demands, if met in full, would have caused a default. There's no practical difference between wanting a default or wanting policies which will cause a default.
In fact, they probably weren't thinking in those terms at all: None of these men were the types to overly concern themselves with high matters of state.
That's very important. While Shay and his followers didn't know and weren't concerned with the long term results their demands would create, those results would still be caused by their actions.
A default and the economic chaos that would follow would have been an unintended consequence and not an actual goal.
They actually got a lot of their concerns addressed, even in military failure. A new, somewhat more democratic constitution was adopted, the burden of taxation no longer fell so heavily on the western counties, and ultimately the Federal government assumed state debts, anyway.
Yes they did. Some of the reforms they wanted were laudable, some would have been disastrous, and one of the largest reforms they unwittingly helped spark was the Constitution.