Many permanent jobs are not permanent, they are just lower-paid contract assignments, to be terminated by the company when they hit hard times. I prefer some honesty about the relationship between a company and the resource they hire, so I work purely on a contract basis.
The example you give is yet another reason for companies to at least consider hiring contractors when predicting future needs, and also why governments such as the UK should stop stigmatising contractors, and enacting poorly thought out legislation such as IR35.
There are many occasions where companies need a flexible workforce, from experience working with finance companies in the UK and Netherlands, they will typically face compliance legislation that leads to peaks in software development tasks, as one example.
When predicting growth, why not hire contractors to perform initial implementations, and hire permanent when the growth is actually realised, to consolidate?