its no surprise that some manufacturers of gear resort to meaningless specs like frequency response to 30khz to try to sell their wares... for tweeters, it often less about frequency extension, rather more so about the flatness of response through the audible range, managing ringing/resonances, which are usually excited during musical transients being played
that said, one man’s rolled off is another man’s natural and balanced sounding... then there is always the room effect, which generally overwhelms more minor differences in speaker frequency range output in any anechoic situation, couldn’t be farther than real world.... haven’t yet met someone who could hear a speaker without a room it sits in...
another thing to bear in mind is that what was right in terms of voicing components 10-15-20-25-30 years ago is not wrong today, it has also been about synergy through the chain using system components of the day -- shrill early cd players, screechy lean solid state amps, tipped up mc carts, rolled off classic tube gear.... optimization and balance of all such aspects has always been what it’s about in successful system building