Remember that Oreo for T-Mobile isn't the same as Oreo for AT&T, or Verizon, etc. They're all modified from the basic OS.
True, all the carriers do that. Yet the other carriers managed to release their customized versions of Oreo six weeks ago. Furthermore, T-Mobile is making the situation worse by their lack of candor:
For three weeks, T-Mobile didn't even acknowledge that they'd suspended the update, leaving customers to waste time trying to figure out why they weren't receiving it when others had.
Even now, T-Mobile hasn't disclosed the reason for the suspension, leaving customers who did receive the update to worry if the problem might be a serious security flaw.
For prospective new customers, T-Mobile has continued, for four weeks and counting, to falsely advertise the Note8 as having Android 8.0 (Oreo). There is still no announced estimate as to when the update will resume.