Hi, is the cocoonababy safe for newborns?

Red Nose recommends to always place baby on their back on a firm, flat (not elevated) surface.

Mamy products, like the one you describe, do not allow baby to be placed flat for sleep, but have an elevated surface.
Please refer to the following:

Red Nose - sleep surfaces
https://rednose.org.au/article/why-is-sleeping-babies-on-firm-surfaces-so-important-and-what-are-the-risks-if-you-dont
Product Safety - sleep hazards (inclined/propped)
https://www.productsafety.gov.au/products/babies-kids/kids-equipment/sleep-related-hazards-for-infants