With a new level 120 boost being datamined this may suggest that we’ll get a new expansion announcement at Blizzcon.
If i recall correctly we got to pre-order BfA around January and we got the boost.
8.2.5 is likely going to be here around Blizzcon so announcement and then 8.3 details, leading us to the expansion, or 8.3 just before at some other event.
We’ll likely have about 6 months of this major patch making it about December/January. Add six-eight months from 8.3 and then the new expansion late summer or early autumn next year.
It would work about the same.