There's ALWAYS constant monitoring. Teams of people all over the world collect samples from humans, other animals and birds, day in, day out. We should all be grateful to them.
The Chinese response said they're stepping up observations of respiratory viruses because they expect more of them. That's entirely reasonable.
Wrt HMPV, the link you posted calls it a respiratory virus that typically causes a mild infection similar to a common cold. No need to panic about this one!