Reason is none of these words actually appear in the tweet body. It is not 'mute meta data about tweets' it is 'mute words' which presumably only are in the tweet body.
You can't mute tweets 'Sent from Android' why would you be able to mute tweets based on Twitters internal meta data?
Direct quote from Twitter "Hi Ian, muting these keywords won't actually change the number of suggested Tweets in your timeline. We are exploring ways to improve suggestions to allow you to further customize your timeline. More to come!" source - https://twitter.com/TwitterSupport/status/122087242860531712
Reason is none of these words actually appear in the tweet body. It is not 'mute meta data about tweets' it is 'mute words' which presumably only are in the tweet body.
You can't mute tweets 'Sent from Android' why would you be able to mute tweets based on Twitters internal meta data?
Direct quote from Twitter "Hi Ian, muting these keywords won't actually change the number of suggested Tweets in your timeline. We are exploring ways to improve suggestions to allow you to further customize your timeline. More to come!" source - https://twitter.com/TwitterSupport/status/122087242860531712