First off - Welcome to the site, Tracey.
The hatches are different. There is additional reinforcement in those bearing factory spoilers.
Having said the above, VW engineers tend to err on the side of safety (as they should) and the rear hatch certainly seems solid. People have been installing aftermarket spoilers on New Beetles for years and are now installing them on Beetles too. I've yet to hear of structural failures - which does not mean there aren't any - it just means I've not heard of them.