I can sense the frustration at this triumph of marketing over practice, but I'm somewhat sympathetic to Lucasfilm's motivation in encouraging this assumption."Tiered canon" is a fancy way of saying "not canon." Star Wars fans have always assumed that their tie-ins were canonical, but that never passed the smell test.
The tiered-canon concept for the Star Wars franchise was codified in the early Nineties, when there was zero filmed Star Wars content but an abundance of filmed Star Trek content--any given year from 1993 to 1999 featured more live-action Star Trek than has ever been produced for the Star Wars franchise, an imbalance that has continued to be true overall, so Lucasfilm has a vested interest in its audience believing that the content released more often "counts" in an atypical way and thus imposed consistency amongst that content (as mentioned earlier) to an extent that's also atypical (then and now).
And it worked, but the reason for wanting that perception to work arises from different priorities at the corporate level.