Do you have a link to the simulation?
Yes, group delay improves due to the lower slope of the cabinet-induced high-pass filter. Of course you lose low bass, but then the subwoofer takes over. Coupling to a subwoofer is probably a little less complicated with a closed satellite speaker.
Depending on the level requirement, I nevertheless build satellite loudspeakers, i.e. those that I develop for combination with subwoofers, in bass reflex. The port then contributes a portion of the level at the crossover frequency, so that the bass-midrange driver is relieved of some of the load there.
Speaker development is a bunch of compromises.