I'll hazard to say unlikely from Pharos as this is part of Beacon.
We also have other tools like HP Web JetAdmin and Zabbix for monitoring and pulling info like this in our shop. And if Dell cleans up their Print Essentials product...
We would find this feature helpful in our environment, as our devices are named by serial number and we use it as the unique identifier to align data between disparate systems.
There are definitely instances where having the serial number would be useful, so I can see the benefit of it.
From a development perspective, it shouldn't take very long to add it (providing there is somewhere in the device record to store it) Pharos are already collecting the make and model via SNMP, the serial# is just another oid that can queried at the same time.
I think this would be a good feature! Sounds like a feature request