HTC has been pretty quick in updating its One series of handsets to the latest version of Android. While the company has not yet rolled out the Android 4.4.3 update for the One M7 and M8, a firmware did leak for the former indicating that a roll out is imminent.
Now, it looks like HTC might directly release the Android 4.4.4 update for the One M7 and M8 sometime during the July-August period.
The leak comes courtesy of LlabTooFeR, who has been pretty reliable with information about HTC devices and updates in the past. He also confirmed that some of the older devices from HTC like the One X, 1st generation Butterfly and other low-end handsets have reached their EOL (End-Of-Life) and will not be getting any further software updates.
Regarding the Android L update, LlabTooFeR says that HTC is still evaluating which devices from 2013-2014 would be getting the update. The final decision, however, can only be taken sometime in September-October, since the final hardware requirements for the OS are not yet known.