Limbo land? You are joking right? Seniority cascades downwards, hence the discussion about resulting training costs.
My estimates may be out regarding variable costs of sim training, but not by much: they are currently training extra trainers at great cost for the expected rush. Also, simulator time is costed internally...nothing is for free. And they will likely have to cancel many commercial slots from which they would otherwise generate revenue. Also, fixed costs have to be assigned somewhere-they do not exist in a vacuum, so this training needs to be costed there as well.
Oh...airbus may quote 12 days...good luck with that. At QF the first two weeks are spent in the classroom, then fixed base takes another month, then 12 sims in 36 days minimum, etc etc.
Revenue generating line training...I will grant you that, in the final month, but there are also additional costs with safety F/Os, check pilots, etc. and often line crews get displaced for extra costs incurred as well.