HP Machine is not a threat to POET.
HP Machine is a purpose built product concept designed for Data Centers that is 4-5 years away, if built at all. It will cost many 10,000 or likely many 100,000 of dollars and be one way to address a solution for Data centers only.
POET applies to almost all electronics devices that have a processor...the applications and vertical markets are WAY wider and broader. Ie. Smart Phone, PC's, Notebook, Tablets, Switches, Optical devices, etc.
Even if Machine was created in 2019, the need for great competition (IBM, Cisco, Lenovo, Dell) for the data center space will be huge, in addition POET will likely be in it's second generation at that time...much more cost effective, diverse and pervasive across the industry. POET can be used as an open standard in the industry (HP Machine is proprietary HW and OS) for example, much like Wintel or Linux on Intel machines.
Take it from someone who knows little about technology...do not worry about HP Machine....it is not a factor affecting POET -full stop. It does not worry me one bit.