If you had already updated to LYZ28N, you can't sideload the OTA image as the available one is for LYZ28M. Your options would be to either wait for T-Mobile to (hopefully soon) release a working OTA to update from that build, or to flash to original stock image (which is what I did - reposted Google's 'dummy-proof' guide
here).
I would like to think T-Mobile will (reasonably) quickly get out an OTA, within the next 1-4 weeks, but if you're in a rush or if battery life is an existing concern for you, go ahead and flash it. I'd never done it before, am not terribly tech-inclined (on computers, at least), and it was easy. And 'Doze' is
the real deal!
Edit: chuckling over the fact that I had to use the term 'dummy-proof' instead of the normal _____-proof as that 5 letter word is auto-censored...