Just want to focus on one point:
They’re not going to draw hype away from Shadowlands launch, and they’re not going to push TBC until a year from now at earliest, since doing so would step on AQ40’s raid tier and Naxx’s raid tier.
While likely true, keep in mind that BC back in the day was announced more than a year before its launch, essentially, it was announce when AQ was fresh content. I see an announcement honestly soon.