I think that would primarily depend on your own post graduate plans, and what field you want to work in. The ISYE curriculum does offer some data science classes, however I doubt that they go to the same depth as data science major classes would provide.
This is a great question – hopefully I can provide some insight. I’m a UW student in ISYE (senior) and am interning in Supply Chain at a large US Defense contractor. I’m coming on as a full time SC Analyst when I graduate. Data is super important to Supply Chain at my company because it gives us metric that we can use to monitor our performance and see where we can improve. I worked a lot with data at work recently, but I’m no data scientist. We have data analysts in Supply Chain, and if you want a job like that (where you’re pulling data, creating reports, analyzing performance, and sometimes working on improvement projects) then a Data Science major would greatly benefit you. On the other hand, I’m just a Supply Chain Analyst, meaning I mostly work on implementing those improvement projects for our Supply Chain. It’s a better job if you’re looking to get into managing and directing parts of a company. While I work with data sometimes, I would not need those specific data science classes – I can do everything I need with good Excel skills and Tableau.