No it would be fine. A tad more bitter perhaps, but still tasty I'd imagine.
You could leave out the sugar too. The point of the simple sugar in the original recipe is to "dry out" the beer because it uses ~1.5kg of malt. If you're just using 1kg spraymalt you don't really need the sugar - it will just raise the ABV and thin out the beer. You could also use 1kg of malt and half the amount of simple sugar (250g).