Could they not get more juice out of a single, modern server? I get porting over to a new system and migrating is a huge time suck and a good enough reason not to do it if everything is working, just seems excessive for 14 cores.
They could probably get more performance out of one core on a modern phone, never mind a single modern server. But you see some really old systems in a lot of equipment, not because the porting costs are expensive, but the certification of proving the new system works the same is more than the operational cost of the legacy equipment.
It probably would save operating costs, and probably over a reasonably short window, if it was done successfully, though.
Maybe the software they use won’t easily run on a modern server.
You could ask them, but you might have to hook up your modem and try to call them. Maybe they have a BBS you could leave your question on.