Blockchains don't have to contain proof-of-work as long as the values in the chain itself aren't valued in and of themselves over longer time periods. In Bitcoin, a cryptocurrency built using a blockchain, the values represent debt owed to someone in exchange for a real world item, and that debt stays active for the life of the entry. There are a slew of proof-of-somethings that allow blockchains to become cryptocurrencies. I don't exactly ascribe to these ideas of value store as related to compute provisioning, but I suppose there could be some actions which might benefit from it, such as certain types of licensing.
That said, triggering provisioning using cryptocurrencies is likely to be a thing at some point.
