>By raising debt rather than equity, it doesn’t have to worry about poor signaling from a down-round raised at a lower valuation than the $8.5 billion it set in June 2015.

How is the signaling from this any better? It still plainly reveals that the previous valuation is not representative of reality. The only difference is that we don't have another imaginary number to outright replace it with. And can we all agree to stop parroting valuation numbers based off investors buying preferred stock?