Agreed. It's the only reason. It's not because someone likes their neighborhood.
The largest distribution of data centers in the US is clustered around the populations centers. Within a radius of 200 miles of Allentown is a massive portion of the data centers in the United States. The Eastern US has the bulk of the data centers...staying in Palo Alto would be ridiculous.
https://baxtel.com/data-center/united-states
Poet's partners AND customers are in this area.
If Poet was an app developer for food delivery I may find this move odd but I see it as 100% strategic.
PS. Amazon HQ2 will be in Virgina - with so many of their data centers.