OK, all you loyal T-Mobile HTC One S onwers. (That'd be those of you in the U.S., by the way.) That maintenance release that was delayed a week should be pushing out now. Improvements in software version 1.84.531.2.710RD include fixes to the splash screen, the voicemail notification not showing up when on Wifi calling, improvements to Wifi calling itself, fixes to the camera and signal fluctuations.
Do note that TMo has said there's no manual download option for the update, and you'll have to wait for it to push over the air. It's not clear whether that means the server from which the download originates will be obfuscated, and thus no manual download will be possible (that's hardly unheard of these days), or whether it's referring to an RUU or something. Keep an eye out for the update and logcat at the ready, and we'll see what's what.
T-Mobile says the update will be pushing through July 7.