In terms of redundancy cost, a lot will depend on how they employed the services of the academy staff.
It is common in sport for organisations to engage the services through a PSC (limited company), and give them yearly contracts through their limited company (I’ve worked that way for many years with England Athletics). If the academy staff were employed that way then there will be zero cost to the football club. If however, they are contracted employees of Scunthorpe United then undoubtedly there will be significant redundancy costs.