It won’t be this Friday, and I’d like to take a moment to explain why.
Early during Patch 2.6.7’s development, our engineering team raised concerns about the extremely small window in between patch launch and season launch. In short, they were concerned that, as often happens in software development, if something critically breaks with deployment of the patch, they might not have time to resolve it before the Season launches globally. Three days isn’t very long to create, test, and deploy a hotfix, assuming we receive reports of it quickly enough (and it’s actually less time - it’s closer to a little more than 2 days as the season launches at 5PM Friday in each region, and that occurs on Thursday our time for players in Asia).
We decided the compromise was to have at least one week downtime between patch deployment and season start. That gives us a more forgiving window to address critical issues, should they arise, and we plan to continue using this format moving forward to ensure we’re launching each Season in as strong and stable a state as possible. It also allows us to provide a more reliable Season start date going forward.
Communication this time around was lackluster, and that lands on me. I overestimated the amount of work I was capable of getting done in a very short, inflexible window. For that, you have my apology, and my team’s already making changes and adjustments to better address that for future Seasons.
The Season preview blog is coming tomorrow, come hell or high water, which is what I’m currently putting the finishing touches on. 
That will include the Season start date. In the future, that blog will ideally land before patch launch (as it has in the past), which should give most of you a larger window for planning your Season start plans like taking time off or scheduling play time with a group. I’m taking ownership on and improving the things I have control over, and trying to plan better around those I do not.
I love my Diablo community, and will always strive to do whatever I can to improve things for everyone. 