My take on this, although it is not entirely clear from the article, is that Epic wants to move most of their computing to the cloud and Google felt left out an

My take on this, although it is not entirely clear from the article, is that Epic wants to move most of their computing to the cloud and Google felt left out and now they have a hospital chain who wants to partner which gives Epic a reason to add Google cloud compatibility (i.e., a customer will pay for the translation). There are a variety of things that might happen to the data once it is in the cloud. AI's can be trained on all the patient data and look for correlations (such as "all doctor X's patients do poorly" or "Unit 12 is responsible for most sepsis problems".) AI's are NOT going to be making a diagnosis any time soon, the doctors won't stand for it, and there is no AI capable of it yet. Even AI's that inspect radiology can only report to a real radiologist who then has to make their own decision (and is legally responsible for that decision.) Another use of the cloud data is to aggregate data across many institutions, mostly to allow medical studies. The NHS in Britain has all their patients in one database which allowed them to do incredible studies related to the Sars-Cov-2 pandemic. Currently the US has no such capability, all that data is in silo's in each health institution, each with their own data formats and their own workflow. Get all the data into clouds, all in the same format, and it can be used for medical research across a much larger population. There are privacy concerns, but there are very desirable benefits to everyone. It would be preferable if government got involved rather than having industry do this for profit. The forced change to electronic health records would have been the perfect time to do this, but the lobbyists won instead so the US health datasphere is still highly fragmented. Migration to the cloud might be another opportunity to fix the problem.