What private records do they have/ can they get access to?
The article mentions as sources: insurance claims (ACA only or more?), Medicare, Medicaid, fitness trackers (what info is available there?)
Are people rethinking seeking diagnosis or care or self censoring when seeing health care providers?
There's no reason it must be limited to ACA plans but it could be. The federal government already has a lot of this data from private insurers and can combine it with their data on a limited basis. This reads as they're attempting to broaden that basis to generalize that combining instead of purpose-specific use cases. Or they go nuclear and force private insurers to provide all this data which seems unlikely.
Fitness tracker data is likely to be limited to what you've agreed to share with your insurer or hospital system. This is often an incentive-based program, perhaps sharing how often you exercise and getting a gift card if you meet criteria. The federal government already has some of this data, up to all of it that they're discussing here. Or they go nuclear and force big tech to give them all the data which seems unlikely. That's pretty unlikely imo because those companies pay incredible amounts for that data in the form of developing free-to-consumer applications that collect this data and they use it for advertising I.e. their revenue.
You omitted or missed these other sources
Medication records from pharmacy chains, lab testing and genomics data from patients treated by the Department of Veterans Affairs and Indian Health Service
The first one newly relates to private insurers only, except the subset they already have, since the Fed has this Medicare and Medicaid data. The latter they already have too but it's historically been difficult to get access to combine it with other data.
To emphasize, without detail it's difficult to get too worked up about a registry of disease. This could be as little as standardized code that pulls this together in a standardized way to ease studies. Things like that already exist in both federal and private healthcare analytics for all kinds of diseases. Frankly I'd be unsurprised if this is them publicizing and trying to take credit for something that already exists =). Maybe they're enriching the data, maybe that only enriches it a small amount compared to just using Medicaid data.
I have concerns with this, and others can reasonably too not even for slippery slope reasons. The slippery slope is incredibly evil and this very, very slightly makes that slope more likely. But it isn't definitely, inherently a mustache-twirling evil plan. Again, an effort was undertaken under the Biden administration to identify pregnant women on Medicaid that was similar to this on the ground. It was hugely helpful. We should be wary lest, had that work completed in 2025, we'd have decried it as an anti-abortion slash welfare queen witch-hunt.