I think it might be simpler for May and the Conservatives, Andhowcould, because they could bumble along pretending that the Irish border isn't a real problem, or if it is it'll sort itself out, and if it doesn't it's someone else's fault, etc, etc. In fact I think a lot of UK politicians would quite like to be rid of the North and all the problems it brings (though May's acceptance of and payment for DUP support is a bit
).
But it wouldn't be simpler for Ireland, not at the moment. In fact, over the years, although there is a sort of Nationalist vibe in Ireland that means outsiders might think we are all in favour of reunification, when push actually comes to shove most of us (North and South) realise that said unification would bring massive problems, both financial and from the point of view of security/policing, not to mention the very different attitudes of most of the populations of the two countries.
Ireland isn't in the best of places atm to deal with all the expense and hassle reunification could bring. Even if the DUP would countenance it, which I can't see happening at all, ever.