The tag is shared, but the system-msg tag doesn’t include total months in its message so it ends up looking just like a normal sub for any client that is just displaying the parsed system-msg
from the example above, currently it is:
system-msg=tduva\sSubscribed\swith\sTwitch\sPrime.
but it should be this:
system-msg=tduva\sSubscribed\swith\sTwitch\sPrime.\sThey've\ssubscribed\sfor\s45\smonths!