Did a Google search, then another targeting Reddit, Amazon and xda. The only thread regarding issues with the update is this one here on AC that you created, the one you created on Reddit and the one you created on xda that got closed. You are literally the only person who has started a thread on this update.Real is relative....
If you want to contact T-Mobile, review the plethora of reports on Reddit, Amazon, other forum sites, etc. There have been people who have reported that the updated caused their device to fail, bootloop, etc. One even said tech support told him not receiving texts was an early indicator there was gonna be an issue etc. The truth doesn't need to be validated by ignorance....
Seems to me if there was a widespread issue, it would be posted somewhere else by someone else.
Also, the update is still listed on T-mobiles website. When they deem an update bad they pull it off their site.
You've been pushing this "there's a plethora of people complaining" thing for a while and there's just not. The only thing I can suggest is you take the advice you were given on xda and return the phone. If your past the return period then sell it. But enough with the nonsense already.