Yes, at this time, Atlas only processes RGB data from RedEdge. RedEdge captures each band in TIFF format, each with a separate imager and a global shutter.
Sequoia stores RGB images in JPEG format, which is not presently supported. Another issue is that the camera uses a rolling shutter, which can cause distortions in the image and complicate processing. A rolling shutter does not capture all parts of the scene at exactly the same instant. An example of the type of distortions this causes are show in the visualization below. Regardless, we hope to support RGB processing for Sequoia in the future.