This is correct for the "first generation" with lugged frames. The tubing changed in 1994, when they went to tig welded construction, and the 750 was back to a 27.2mm seat post. It stayed that way through 1997, which is the last year of the 750. The 750 continued to use True Temper branded double-butted cro-moly steel in 1994-1997, but I guess the wall thickness changed to allow for the larger seat post again.

The 730 became the highest trim steel MultiTrack in 1998, and it was upgraded to use a 27.2mm seatpost (up from 26.6mm in 1997)...at least according to Trek's technical manuals.