I can think of a couple of reasons to use the SR-71 again.

• Concern that a crash in space could lead to a cascade of crashes, disabling all sattellites.
• (On demand) capacity. I could imagine that the SR-71 can cover an unplanned spot faster than sattellites. Also, with the wars in Ukraine and Iran they're maybe finding out that they don't have enough imaging capacity.
• The imaging angle, a plane can image almost horizontally, they can look under bridges, through windows etc.
• A ten times increased resolution could be useful for recognizing details, maybe it's even good enough to recognize people though it might be pushing the limits of facial recognition. It's also the kind of resolution where they can read some text, e.g. identifyers on shipping containers or military vehicles.

realistically, I don't know what you'd use it for unless you need extremely high-resolution images.

Well, what does NASA do?

I think it's a pretty safe bet that NASA wants it to test something about aerodynamics at extremely high speeds. Perhaps they want it to deploy some experiment at mach 3. Sometimes you just don't know if your simulation models are correct, and you need to try something in the real world.

I suppose it's also possible they want it to get some close up footage of a rocket during launch or reentry.

But I think the most likely answer is still that they just need something that goes very fast.

Satellites are too predictable, plus too infrequent. If there are two spy satellites that cover Iran, for example, Iran can easily know when and what direction, then presumably take some effort to cover whatever they want to hide.

A reconnaissance plane can show up without warning, any time, loiter for at least minutes, take pictures from different angles, in addition to sharper imaging. We can speculate they may also have sharper non-optical imaging, such as thermal or radar

My money's on hegseth wants the sonic booms when he's giving a speech about how manly the army is. Considering they have that unmanned x-37B for spy satellite stuff, and it would be a massive amount of money to bring back the blackbird, while NASA is having its budget cut, it is 100% going to be for some self serving promotion.

I would just like to point out that while not confirmed, it has been speculated since the mid-2000s that the actual imaging resolution of the satellites is closer to 2mm. Or as the joke goes, we'll figure out what brand of cigarettes you smoke by reading the filter.

NASA flies U-2 spy planes over wildfires. They might be able to do the same thing with the SR-71. I really don't know, that's my best guess for a realistic use case.