I know what is the situation for Cortana and how Microsoft is moving slowly about it. Moreover, Paul and Brad discussed the situation many times in articles and podcasts. However, I think Microsoft revealed more about their strategy. Their OEM introduced 2 laptops at IFA, and I quote from The Verge that “Lenovo’s Yoga 920 laptop is basically a home speaker. It responds to Cortana commands even if it’s closed and you’re more than two feet away. Acer’s Spin 5 convertible features Cortana and can register commands up to 13 feet away”.
I could be wrong but I feel that Microsoft might think there is no need of standalone home speaker if you can use your PC or your laptop as a home Speaker.