I am aware of placements being offered to graduates who have completed their courses this year, so a "hold pool of 18-24 months" seems highly unlikely. However given the tidal nature of recruitment and the commercial demands of the airline customers, such things should never be dismissed. In the past few years there have been waiting times for placements of anything between zero and over 12 months.
I am sure you are also aware that the latest offers ( in orange land ) were seasonal. I know of a couple of flexicrew "enjoying" a winter sabbatical. November to March off. A promise of re-employment in a base subject to company requirement. So we now have a flexible and migratory workforce.
I personally would not consider entering the commercial flying world at the moment. The numbers do not stack up.
Bealzebub is glass half full. I am glass half empty.
You should also be aware that the orange lot have also offered unpaid leave over the winter months to their employees. Not allowed over Christmas period though. So we are overcrewed in winter. Combine this with very limited expansion and you can surely see that command and employment opportunities will start to dry up. This is in one of the most profitable airlines in Europe.
So Wanabees " Take your chances "