You can't trust Emerick on this. It's certainly possible to subsidize industrial or commercial electricity by over charging residential users, but that's not usually the direction the subsidy flows because of politics.I'm just telling facts. Residential customers will be on the hook for the upgrades to substations and generation plants because Entergy add those costs to the rate base. Why do you think the president of Entergy MS is in an all out propaganda war with the Northside Sun journalist that uncovered this fiasco. Sorry you're to bias too see it.
Data centers don't have the best load profile for summer peaking utilities (I think their peak demand is usually around mid to late afternoon, I guess a combination of a lot of IT work from businesses and daytime heat driving demand associated with cooling), but it's generally a better load profile than residential, which has a relatively lower baseload demand compared to its peak.
A lot of people also make an argument that depends on attributing the cost of new generation capacity to new load, which is not a crazy position but it's also not obviously the correct one. I think it's just as reasonable a position to treat new load and existing load as equally responsible for the cost of capacity. Existing users don't have any claim to existing capacity and it's perfectly reasonable for the cost of electricity to be born by consumers on the same basis regardless of when they started pulling power from the grid.