According to renowned ROM developer @LlabTooFeR, HTC is set to release their latest Sense 7 update to HTC handsets released this year, which of course include their HTC One M8 flagship. However, this doesn’t include all low-entry devices, although some of them may still have a chance to receive it.
From what we know, the HTC Hima (HTC One M9) will be the first handset from the Taiwanese manufacturer to be shipped with the latest Sense 7 UI next year.
Source : @LlabTooFeR