Yes, myCloud supports these file formats when uploading, viewing in the gallery and in the details view.
However, you should note that these formats cannot be processed by all softwares yet. Thus, viewing them outside myCloud cannot be guaranteed.
If you want optimal compatibility with all devices, we recommend that you change the default settings on your device and use the ".jpeg" file format as the default format for your photos.
To change these settings on your device, please go to:
Settings -> Camera -> Formats -> then switch to "maximum compatibility".
When downloading via the web, the images are converted directly to JPEG to avoid compatibility problems. More about this here.