There have been good points on all sides of this debate so far.
I approach the problem thusly:
A fundamental conceit of the Traveller universe since its inception is the idea of blade combat being a fundamental element of space travel:
* The prevalence of "Melee (Blade)" in the specialization tables for spacefaring careers.
* Certain descriptions in the text, e.g. the "Weapons Locker" is described to contain useful items such as cutlasses for use in repelling boarding actions.
Now, if one assumes that all the "pro-FGMP" folks are correct and the most powerful/efficient weapons would be used in a boarding action then the cutlass would be hopelessly obsolete - just as it is today. Nobody in Iraq on either side is charging into a room-clearing operation with a cutlass on their belt. Japanese officers in WWII carried katanas, which were useful in close combat, but even carrying a katana was mostly a symbolic gesture.
Approaching the problem from the other angle - i.e. "because cutlasses and blade combat are given special importance by the Traveller rules, then the use of blades must be the most effective method for repelling boarders" - gives you perhaps an "unrealistic" result, but also a result richer in flavor and unique from other SFRPG.
Brutes in powered armor with energy weapons? Done to death by any number of games, novels, films and anime.
Desperate battles through the corridors of a spacecraft using ringing steel? A bit more original.
So, for that reason alone, I lean toward the latter approach. YMMV, of course.