I think there should be a separate codepoint for � when its usage is intentional as a reference to the replacement character 
-
-
Replying to @wycats
Fake “Boonicode.†↙️ Retweeted Yehuda Katz 🥨
Then how would you refer to it?
@wycatshttps://twitter.com/wycats/status/735874305582616576 …Fake “Boonicode.†↙️ added,
3 replies 0 retweets 0 likes
Replying to @FakeUnicode
you could use the JavaScript `undefined`
10:10 AM - 26 May 2016
from Munich, Bavaria
0 replies
1 retweet
1 like
Loading seems to be taking a while.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.