If Celestial is committed to using Poet solutions then there is NO way that they would give that commitment if they thought Poet would run out of cash.  Therefore they understand the Poet has sufficient cash or would support them through some sort of supplier agreement with some accelerated cash maybe in exchange for better pricing. 

Or, they could take the view that if Poet went bust they could pick up the company on the cheap to vertically integrate the supply chain.  The hole in that strategy is talent might leave  and /or they could lose out to a purchaser with bigger pockets which would really stuff them.  That would, in my mind, be too much of a risk and personally I'd  discount that scenario .

The lack of cash runway is a nagging problem but a little voice in my head says don't worry - its sorted.  I do hope so.