Definitely. As long as the game cartridge isn't digital both game cartridges should still work on your new nintendo 3DS and you'll have two seperate towns, it won't affect your saved data at all, by the way.
Oh damn. That was gonna lead to my follow-up question: If a digital copy and physical cartridge can coexist without corrupting one another? But it seems not
I have a digital and game cartridge on all my 3DS. All still work. The first digital copy was bought a month after the release date.
It still works.
If you haven't got the streetpass badge yet make sure to open the town that is working on that badge first.
I lost a lot of tags to my guest town in the first year. Opened it first.
It won't let you have more than 1 digital per system, you can't download more than one from the eshop to the same system. You can have as many physical ones as you want, there's no limit since it saves to the cartridge, not the system.
