Proprietary software developed by a (smallish) company is stored in the company's GitHub private repository. For work, software engineers are requested to create company-specific GitHub account bound to their work email address.
But access to the private repository can be granted or revoked independently from the "account origin". What can be the risks of using personal (i.e. associated with an email which is not related to the company) GitHub account by developers?
Edit: I see one potential risk: if the account is used also for other things than work, its SSH key is likely to be saved also in places where these "other things" are done. This is a potential threat to work repositories; with a dedicated account, it's easier for the developer to keep the key(s) only in work-related (maybe controlled) environments.
Are there any other specific risks?