That's the Spanish board game called 'Trench', which is a trademark. According to Eurogamer that trademark covers both board games and video games in Europe. Consequently unless Microsoft either finds a way around the trademark, retitles the game, or points out "look they're completely separate words, you wouldn't ban Nancy Drew: The Mystery of the Clue Bender Society because it has the word 'Clue' in it would you?" the game will remain unreleased.
I just want to play a tower assault game with mechanized trenches against a race of vicious TV monsters in a World War One scenario, is that so much to ask??
Source: Eurogamer
Logic
Not to mention the ridiculousness of trademarking a single generic word which is in common usage. Aren't there distinctiveness criteria for trademarks?
Apple
But yeah, this trenched thing is pretty ridiculous.