Technically speaking, Google Assistant has had native support for smart blinds and shades for a while now, but it was limited. Some brands, like Lutron Caseta and NeoSmartBlinds have had it implemented, showing you a special icon in the Home app and letting you immediately ask Google to lower the blinds or open them. But for most developers and smart home makers, the APIs weren't documented. Now they are.
A new section for blinds has been added to the Google Assistant documentation for developers, outlining support for various modes as well as open/close actions and percentages. Hopefully, that means that more brands like MySmartBlinds, SolarGaps, and Soma (which I reviewed) can now skip the "ask service_name to open the blinds" vernacular and work on a straight native implementation.
This isn't as outlandish as the recent support for smart fireplaces and air fresheners, but the more device types can talk directly to Google, the better.
- Google Developers