Nova Scotia refused because the political elite (Halifax merchants, mostly) had it good with contracts with the government. Two tiny movements did break out, the one involving Jonathan Eddy at Fort Cumberland and the other involving John Allan at what would become Saint John, New Brunswick. Both were huge flops. It's quite hard to get a rebellion to succeed in Nova Scotia for four reasons:
1. The rebels had pissed off a lot of people with privateer raids along the coast. Pillaging communities is not an effective means of encouraging volunteers to join your cause.
2. A lot of the settlers (the Yorkshiremen, Ulster Protestants, the returning Acadians, etc) just didn't care. They didn't have a horse in that race. The ones with revolutionairy sentiments by and large were the settlers from New England. There was also a religious movement ongoing in the form of the New Light movement which sapped support for fighting a war from many.
3. The Continental Congress did not think it wise to commit resources to any campaign in Nova Scotia. The geography is very unfavourable to a land assault, and a naval assault was virtually impossible given the large Royal Navy presence and lack of a Yankee one. Add to that that the fuckup that was the invasion of Canada and the rebels had no confidence of success, which is why they denied Eddy the support he requested.
4. The naval station at Halifax had quite a powerful garrison, one which can easily suppress any attempts at revolt in the city. In addition, the scattered nature of settlement in the rest of the colony prevented attempts at organising an effective rebellion in the rural areas of the colony.
So, if there was no privateering, and if there was little-to-no non-New English settlement, and if there was no New Light movement, and if the Continentals did send an army, and if they survive the march to Halifax, and if they can beat the powerful garrison of redcoats there, and if, and if, and if...