Ive taken a look at a couple of articles Ive found, and really I still fail to miss the potentially big thing about combining the two, more than the current stand of AI processing information on large centralized or decentralised databases.
From the AIs perspective, Blockchain can be considered in essence as a database repository (non- tamperable, distributed, and all we like), so AI can be applied to whatever information resides there, just as with any other DB repository. The context of application is derived from the nature of the information stored in the DBs or on the specific Blockchain. It looks like (evolving) business as usual, but including user case scenarios where the information resides on given Blockchain instead on more regular DBs. There are obvious applications, but due to where the data resides.
Some related articles which fail to provide, in my opinion, a reason to see this as a global breakthrough:
https://emerj.com/ai-sector-overviews/ai-in-blockchain/https://thenextweb.com/hardfork/2019/02/05/blockchain-and-ai-could-be-a-perfect-match-heres-why/