Blockchain isn't a good replacement for functional legislative and/or regulatory bodies that actually give a shit about the people they're supposed to be protecting. In this case, corporations unwilling to grant actual ownership of "digital purchases" to the consumers who paid for them aren't going to change that policy just because it sounds like a cool application for blockchain. If they were willing to do something like that, they would already offer portable DRM-free installers and license keys to match. Indeed, some publishers do exactly that, but Ubisoft's management are the sort of bottom of the barrel scum who will only be dragged kicking and screaming into a world where consumers actually own what they've paid for.