USB Accessories disabled. Unplug the accessory...

If the device disappeared/dropped, then macOS may not know which device it was. Besides, the device which dropped, may not have any problems if the USB bus was utilizing too much power. If multiple devices are using power, then it may just be random which one is dropped in order to reduce the power draw on the bus.

Now for the possible issue here which has not been considered:

Maybe a USB-C port is bad. It does not necessarily need to be in use.

Maybe one of the Thunderbolt devices had an issue where somehow it triggered the issue (or like I mentioned, perhaps the port those Thunderbolt devices are connected has a problem....remember the USB-C ports on that Mac handle both Thunderbolt & USB. Even though it may be using the Thunderbolt protocol, a defective port may for some reason believe USB power is being used.

Maybe it was not an external device. Some internal components actually use the USB bus such as the built-in camera. I'm not sure how the built-in keyboard & trackpad operate these days, but historically they were USB devices as well.

Maybe there was a power issue with the SanDisk drive, but it recovered quickly enough so not to affect anything.

A defective cable could also possibly trigger a problem.

If it keeps occurring, then you are going to have to experiment and leave one device disconnected until you discover the culprit. You may even need to inspect the internal contacts of the cable connectors and even the contacts of the USB-C ports of the laptop, however, those contacts within the USB-C port on the laptop are very hard to see clearly. Many times I have thought they were clear, but after taking the laptop apart to get a clear view of the ports I discovered corrosion or even burn marks. So just because the contacts look good doesn't mean they really are since they are so hard to see. It is amazing how many USB-C ports I find with corrosion from liquid damage (only takes a drop).