@altiplano
No, you're right - its not a requirement to work 2 years on the ramp with a CPL. You could get a job right out of the gate doing many things without additional training costs - sky diving, aerial spray, banner towing, sightseeing, etc.
However, in this case a 300 hour pilot is asking about the ATPL.
It is very fair to assume that they are looking at getting on with an operator who hires low time pilots into the right seat of an aircraft certified for two-crew operations. In this case they need to have either the IATRA or ATPL exams completed 24 months prior to the issue of the PPC.