Though this thread is a year old, I thought I'd add my two-cents. I believe that the Star Fleet would continually upgrade the escape pod designs and mechanisms on all ships of the fleet, regardless of age and design. There's no resign the Excelsior class wouldn't end up with lifeboats similar to Voyager's in due time.
No matter how I look at the various possibilities, I think Rick Sternbach's cube proposal makes the most sense.
After a catastrophic event the lifeboat cubes could easily connect to one another to form a cluster of lifeboats that would eventually resemble a Rubik's Cube. If there's enough space the survivors could move to the interior cubes with the outer cubes providing a protective shell or buffer zone.
I definitely wouldn't like to see lifeboat designs from the later series or movies being retconned into the TNG era. I'd like to see a unique and different design for the TNG era.