That wouldn't be a problem with NFTs as they could just go to another game provider, show their proof-of-ownership and download their games from there. Such import functionality already exist to some limited degree right now with GoG, Steam and Co., but all of them require that your account with Ubisoft is still working. NFTs would work even if Ubisoft disappeared completely.
Furthermore NFTs would allow used game sales, something we have lost with the switch from physical to digital, despite it being required by law in many countries. A signed recipe is nowhere good enough, as that still depends on your account at Ubisoft, e.g. to keep track of if you refunded the game or not.
Now getting the game industry to actually implement and use an NFT based game-ownership system, that's the tricky part. But claiming there is no technological problem that needs solving is ignoring all the freedoms we lost by going digital with our purchases and that could be regained with NFTs.