So, earlier this week there were some leaks of certain content for the upcoming expansion. But in a bit more 'clean' news: http://massivelyop.com/2017/05/02/gu...ely-this-fall/
Basically, we know that there's only one more episode left in the current LS season. According to this article, the expansion should drop soon after, probably still in 2017. It seems they've taken back their pacing of regular content releases (although it is somewhat slower than they used to be) with new content every 2-3 months. Although there will probably be a bit more time between LS season 2 episode 6 and Expansion 2 than there would be between regular episode releases since it's a bit of a bigger deal. The article states that season 4 is already planned as well, which could possibly begin after the initial 2-3 months once the expansion is released instead of the nearly a year worth of content drought that followed after HoT.
It's good to hear they haven't 'given up' despite things not really going as smoothly as they'd have hoped.