Probably at all levels and likely to be worse with outside contractors. QF is still an employer of choice and will be able to attract applicants, however subcontractors with lesser T&Cs who retrenched staff might find it difficult to get them back if they've found better jobs.
Flight may be canceled if for example, no one is qualified to operate the pushback tug at an outstation. The previous employee isn't interested in coming back as he's got a mining job on twice the pay. Finding and training up a replacement takes time and money. Margins have been screwed down and don't leave much in the budget to offer an attractive pay rate and cover the cost of training and certification.