S20 start date was supposed to be released last week
This was posted (and stickied) on 2/14. It states they ‘will be providing a S20 preview sometime next week that will include the start date for the next Season’.
Next week being 2/16-2/22…
I had wanted to (and, way back when, originally planned) to publish it last week. A number of last-minute publishing conflicts and illnesses caused delays.
We intend to ensure the publication of the S20 preview before Patch 2.6.8 deploys in the near future. That should still give you guys a heads up on what’s happening, before it happens. 
I know it’s later than originally anticipated; this is part of why we typically don’t provide time estimations. Things can, and often do, happen. If I’m being honest, I thought I had scrubbed all posts of time estimations for that reason, but it’s clear I missed one. 
That’s on me, personally.
Thanks for bearing with us. 