"No widows" on its own isn't enough to create a distinctive dialog cadence.

"Widows" (alone at the top) and "orphans" (alone at the bottom) are single lines cut off from the rest of a paragraph by a column/page break. The solution is generally just to fiddle with column/page breaks, which is purely typographical.

I'm sure that there's a distinct identity to X-Files dialog; it's just not due to this quirk.

I can totally see a fellow typography geek bragging about this to someone and them being horrified haha.

ETA: I speculate that Carter was avoiding "widows" to be considerate to the actors by not splitting lines across page turns.