"Home rule was in the bag."
Until Lloyd George moved the goalposts.

Nothing was changed until the rising, and then because of the rising.

As it happens, it was always and only the Unionists who offered opposition to Home Rule

They agreed the 1914 Bill.

Conscription.
Irish were excluded before the rising, but a German victory would have been catastrophic for Britain including Ireland.
If that became a real possibility then it would be necessary to think the unthinkable.
In early 1918 that was briefly the situation, but it quickly passed.

Only the prospect of imminent defeat made the contingency briefly necessary.