If you do not onboard any Prisma Access gateways in a region,
an IP address pool for that region is not required. For example,
if you specify gateways in the US East, US Northwest, and US Northeast
locations, you need to only specify an IP address pool for the North
America & South America region. Conversely, if you enable mobile
user locations in Europe without specifying either a Worldwide address
pool or an IP address pool in Africa, Europe, & Middle East,
your deployment will fail.