To date it hasn’t appeared in Beta Testing (you can subscribe to #beta-beat where all new Beta Content is posted).
It also doesn’t appear to be part of the plans for V30 of Beta Testing (click here for a summary of what IS in V30 so far)… Maybe Version 31…?
Also worth pointing out some precedence in terms of the timeline of “sneak peak” features. There isn’t any guarantee tho that what was in the announcement will actually appear in game in 2020… I mean if you look at the Hero Academy, it was first “announced” in 2018… 500+ days later it appeared in Beta… So it could yet be another 500 days before it appears in game (Hopefully not tho…)
→ Teaser: New Year 2019 Sneak Peek!
→ Celebrating 500 days since Hero Academy first teased