Further comment from Andrew Webb, BBC Worldwide VP Product Strategy:
'To expand on Matthew's comments, we do have the ambition to integrate with HomePod and allow our audience access to BBC services, but as yet, we know of no plans to allow third party applications to operate via the HomePod/Siri ecosystem. This is slowly opening up, if you are on the latest version of iOS and you ask Siri for the News, Sport News or Business News you now receive BBC News services. So, we do see a future evolving but we are not privy to their future intentions in this area. There are other considerations other than technical limitations. All BBC content available via 3rd party platforms must comply to the BBC's regulated distribution guidelines to ensure value to the license fee payer.
These are subject to commercial negotiation and often require work from both parties in order to be able to implement. So, the slightly longer answer is, not yet, we do have the ambition though, however there are technical hurdles that need to be crossed and commercial conditions that need to be satisfied.'
This suggests that Apple's support of third party services on HomePod is still very quiet, and the HomePod will have very limited services at launch. It's again encouraging that they are fully aware of the product and are working with Apple in order to implement something in the future, though. But when this occurs is Apple's guess alone.