They either pay you 1 basis when called or they expire worthless, if Basis economy will stagnate/contract for 5 years in the row.
Additionally they rely on unregulated crypto “exchanges” to make secondary markets in these futures.
I think the reason they’re calling them “bonds” is because binary futures and prediction markets are illegal in US (falling under CFTC jurisdiction).
Similar problem will apply if they were real bonds - then they're falling under the jurisdiction of the SEC and will have to be registered with them or get an exemption from registration.
EDIT:
For those who think that MakerDAO is better than Basis protocol, it's not that Maker got CFTC license to operate a Swap Execution Facility (SEF)[1].