Part of me wishes Valve would just go back to the TFC method of using manual entity setups for gamemodes, rather than just slapping on an entity that says "This is a KOTH/Arena/CTF/5CP map; do whatcha gotta do" and barring any creativity. But that would break every single existing custom map in one fell swoop, including the ones that are no longer being worked on.
What they could do, though, is create a gamerules entity for CTF. Fortuitously, CTF currently doesn't use any such entity because symmetrical CTF with flags that respawn twice is the default, so adding one would let designers get more creative without breaking any existing maps.