"Uploading a human mind" means taking readouts of a persons mind and attempting to replicate the readouts virtually, to generate a "duplicate" version.
You don't spend one making the other, so you aren't going to end up with "blank people" ready for uploads.
You could potentially have a BCI active doppler system for integrating a symbiont virtual creation with a real human mind which would allow the training of that virtual creation to go beyond just the initial abstract capture or enhance the human further (Handy for those with brain damage or just missed out on the level of training necessary to tie down a job)