Nope, the majority of them are modded. The last time i played vanilla CTF was on the community game night in January before my A levels. Since then, it's been near impossible for me to find any vanilla ones, the majority have some form of teleportation or stupidly placed vehicles etc. You could try version changer to find some vanilla CTF servers on older patches but i'm not sure which version is the most populated. Hopefully someone else will be able to shed some light on that for you.