What it does: watches your payments for patterns that often come before disputes, so you see them early. When a dispute arrives, it advises whether to contest it or settle it.
What Aperture does on a lost dispute: returns its platform fee on that payment, the same as a refund (Fees and Refunds, section 5).
What it does not do: it does not prevent or eliminate chargebacks, and it does not promise how any dispute ends. The card network and the processor decide.