The future seniors won’t be people defined by strong technical knowledge. They’ll be the ones with “autonomy and judgment” as Anthropic puts it (read: highly social; good at climbing the corporate ladder; strong educational/professional pedigree).

These people won’t necessarily need to be trained in CS, because in 10 years no one will need to know what a data structure is. So they can come from other fields (law, business) or just from other roles within the company.

Note this is basically how it already works in every non-technical field where there’s no clear definable “skill” on which to evaluate people.