It is trivial today to sample audio in a rate and sensitivity which greatly surpass both the density of the pherromagnetic material in the tapes and the fidelity of the original recording equipment.

Even "analogue" sound depends on the resolution of the underlying technology, so no, there doesn't have to be any data loss.

And that's just on the philosophical level, about which our limited ears care very little :)

Four fifths of f-all in comparison to the inconvenience. It's entirely related to monetising the whole thing, rather than giving it away online for free.