--- Want any of my Constitutional rights?, ΜΟΛΩΝ ΛΑΒΕ
I come from a time and a place where I judge people by the content of their character; I don't give a damn if you are tall or short; gay or straight; Jew or Gentile; White, Black, Brown or Green; Conservative or Liberal. -- Note to mods: if you are going to infract me have the decency to post the reason, and expect to hold everyone else to the same standard.
They never announced an 8.3.5 so how could it be canceled? What they actually said is that they had no plans for an 8.3.5.
The only evidence that Shadowlands might be "behind schedule" is that alpha is starting later in the year than it did with Legion and BFA, but until we see how far along alpha is there's really nothing to discern from that alone. Especially since they deliberately staggered the content release cycle for BFA compared to Legion, presumably with the ultimate goal of reducing the content gap between expansions.
The gap between 7.3 launch and 8.0 alpha was 5 months, but we're actually looking at a much shorter gap between 8.3 and 9.0 alpha, assuming alpha drops within the next few weeks -- and, hell, it seems to already be available to third party vendors since there's an encrypted 9.0 vendor build on the CDN right now.