How a T Rex looks is obvious, its size is shown, why is it such a big issue?
We have profiles for bigger skeletons such as the
Sea Emperor Leviatha despite that never shown to be alive
If we can determine what it is throught logical assumption we can use it
It'd be better to say "This profile is redundant because its a T rex" then "We don't know what it was when it was alive", the former makes sense, the latter does not.