Feb 25, 2019
Thanks so much for your interest. At present we do not have the full list of features that will be supported by Google Home Assistant. Stay tuned for a full announcement in the near future!
Patrick A - Community Support
At this current time, Google Assistant integration is still in the works, and we do greatly appreciate your patience. There is no definite date I can provide at present - but it will certainly arrive at some point in the future. Again, I realise the frustrations in waiting for this and we do apologise for that - but do understand we see your posts and we are working to get this out to you. The best advice would be to keep an eye on the home page of the Bose Community for up to date news and updates!
Mar 22, 2019
"Is there any indication of it will be in 2019?"
Yes, it was announced it will become available Spring of 2019
Apr 1, 2019
They're a little ambiguous because they can't give out details, but in 2 posts regarding the 500 and 700 when the question was posed if they will get Google Assistant, Bose has responded Yes and that they will be released in Spring of 2019 and will become available to the existing line without need for new purchases ("This feature will be released with an update and there will be no need for further purchases or accessories").
So to your question, I'd say Yes, Bose is confirming that they are definitely releasing Google Assistant to the 500 and 700 soundbars and will come as a software update in Spring 2019 (assume last day of Spring with a potential 2 month delay). They can't giveout further details at this time (probably because if they promise some detail and don't deliver, the backlash will be huge).
Mar 25, 2019
Thanks for posting and welcome to the community.
The Home Speaker 500 will get Google Assistant when it is released. It will be part of a software update.