World of Warcraft expansion release dates in NA for perspective.
(Timeline summarized from
https://wowwiki.fandom.com/wiki/Time...d_of_Warcraft))
Vanilla : 11/23/2004 (26 months)
TBC : 01/16/2007 (22 months)
WoTLK : 11/13/2008 (25 months)
Cata : 12/07/2010 (22 months)
MoP : 09/25/2012 (26 months)
WoD : 11/13/2014 (21 months)
Legion : 08/30/2016 (22 months)
BFA : 08/14/2018 (Already 26 months)
SdwL : 10/27/2020 (delayed - TBD)
To put in some perspective, BFA is already the longest expansion in WoW history (even before the Shadowlands release delay). This also makes it the most expensive WoW expansion (from the subbed customer POV in WoW history.)
Understandably, 2020 is an extremely challenging year for lot of businesses due to COVID-19. So, some amount of delay is expected.
8.3 Nyalotha patch was released in Jan 14, 2020 and it was announced shortly after that that there would be no 8.3.5. Given that Shadowlands is at least a month away, we have effectively paid around 150+ USD for just the 8.3 content. That's an extremely steep price for even a very premium game.
For reference a AAA XBOX or PS game costs $79.00.
2020 has been tough year for consumers as well; a lot of people have lost their jobs and are taking bail outs. How do you justify maintaining a sub through this with the uncertainty of when the next expansion is? At this point, the logical step financially seems to be to just unsub and sub back in when SL is released.