On the other hand hacking any cryptocurrency, at any stage, cracking wallet or any other hacking related to cryptocurrency is way more complex. Not only you need to have a really good hacking skill, but you also need a big compute power. What I am saying is that hacking printer and hacking cryptocurrency is in far different league.
Hacking Cryptocurrency wallet is difficult I agree, but here it say cryptocurrency wallets can also be affected. If the person might have given a document of wallet for print then the document might have been saved by the printer, which will cause an adverse effect to the wallet holder if he gets the access.