The Acala will support the whole Polkadot defi-sector, not just as a simple oracle, but as an oracle-aggregator. The platform will collect the data from more oracles, and let the protocols decide, which one fits in the best way for their needs.
The defi-fever in the summer indicated development on many platforms, including Polkadot, next to the EOS and Tron. All eyes were on the success of Ethereum, and they want to take the share. Since then the noisy hype is gone, but not the hard work. With this oracle-system, it seems Polkadot didn’t drop the plans for defi.