UPDATE: Nintendo Australia has confirmed to us that this is not the case. They’ve provided a pretty reasonable solution to those who might damage their Labo cardboard bits a long the way.
“We recommend holding onto the cardboard sheets, even after the pieces have been removed from them. Later, the removed pieces can be used as stencils to trace and cut out spare parts from the empty bits of these old sheets.” said a Nintendo Australia representative.
Nintendo has apparently revealed to IGN France that you won’t need to buy the Nintendo Labo kits. They will instead offer free cardboard designs that we’ll be able to download.
You’ll still need to buy the software and it’s obviously unclear how good these cutouts would work in comparison to the Labo kits. You’ll obviously also need to buy the cardboard/hard paper and it’s unclear how this would work for elastics etc.
“Note that the kits will not be mandatory – although the cartridge is needed – since Nintendo plans to offer the cardboard design pattern for free for aspiring builders”