That's not entirely accurate or safe to say.but that is compensated for by raising the level trim of the subwoofer output so that it restores the original bass level for each channel AND gives an additional 10dB increase to the LFE channel.
The LFE is already 10db hot prior to mixing. That remains unchanged.
But more importantly...
If a user cranks it another 10-15db to restore the lost dynamics, and then say say EOT Intro comes along, the LFE was already near clipping (10-30hz), prior to any bass redirection. The center also has bass near clipping (10-30hz) in that movie.
The user's LFE is now 12-18db beyond fully-clipped, and the subwoofer is toast, it has no chance of survival. [and that's exactly what happened to many! ]
You cannot restore the dynamics once it is lost (at least, not without huge risk.)
At the time that movie came out I had everything set to all-large, and was vastly underpowered and even then... that movie almost killed $15k worth of subs in my system (subs that can't be replaced). Subs that had 80mm's of excursion and barely made it out alive!
The rest of that movie had like "no bass" because after I had turned it down to "regular levels" the bass never went the hot again for the rest of the movie! (or any movie that has ever come out since! )
Let's just say: I now have advanced dynamic-limiters and soft-limiters and hard-limiters in place to prevent that from ever coming close to happening again (especially now that I'm not underpowered.)
I also NEVER crank any trims above 0db, to avoid source clipping for that very reason.
Without that, given the amps I have now, nothing would have survived.