(Standard disclaimer -- I am a twice a year line following cave tourist so please forgive what may be ignorance in the following)
I've been on a number of line where the arrows change direction. I do not know, but I have been told, that some of those arrow changes point to "the nearest exit" but that they might not be available to me due to restrictions (side-mount/no-mount). Is it not true that not all "nearest exits" are available ones?
There is an arrow that doesn't even point to an actual exit in Chac Mool. About halfway to the way to the giant stalactite you will pass "emergency air cenote" and an arrow pointing straight up into a hazy murk That is breathable air in an emergency, but you cannot exit there. Is that an "available exit"? (I don't think so) Should that arrow be removed? (no IMHO). Just leave it. If you ever surface there in an emergency you wait. You might get pretty cool after awhile. But at some point someone will coming looking for you and you'll get to exit.