This is just a simple classification problem, the prime application for basic neural networks. Using a general text generation system for this seems like complete overkill. Just a bunch of wasted resources.
This was also my first reaction, but it got me questioning whether I’m just becoming the same as the guys who were saying “using an interpreted language for that is a waste of resources”. Maybe LLMs are the equivalent, sure they use more CPU cycles, but you can point them at some problems and get them solved for a fraction of the effort.