devtrackers.gg
Buddy this has been a thing since at least halo 3. It ain't 343.
CTF flag-at-home rules have always varied and it's a custom setting option. Feels like overall, people are generally split on it. Personally sometimes I like one or the other, depending on map and mood.
What playlist did you encounter this in? I'm told 4v4 CTF should be 'flag at home to score.'