Except it’s not that simple.
Add in the cost of 3 months wages plus hotel & allowances and you can more than double that $40k.
And if/when they are needed again do you rinse and repeat for another $80k? All so you can push out a junior burger?
Besides, unless they were given type / base protection, many of the B787 Captains wouldn’t stand a chance of getting back on the widebody again