I am all for consequences in this game, as I have mentioned quite a few times before this. I am perfectly fine with characters being punished for their actions, whether this is mechanical or through RP, and I also think that death is more of a nuisance these days than something to be feared. What I don't like, however, is that outguilding is used as a threat of punishment for anything other than the more extreme cases, like "You betrayed our entire guild and fought alongside the enemy to kill your brethren!" Even that feels like it would be more likely that the person already has a foot out the door and should be contemplating leaving anyway.
Guilds, as they are now, are less consequential, since the focus is more on the cities. If someone has put effort into a guild, then they should be treasured. They chose to join that part of the game for a reason, and they have probably worked quite a bit for it in order to rise in rank. Some people even put in a -lot- of work, building a reputation, or helping out with making the guild a more fun place to be. Outguilding as a punishment will essentially throw all that hard work out the window.
I find it incredibly disheartening to know that there are players in this game who fear this so much that they don't dare to play out their characters' struggles the way they would want to. The reason being that they break the norm and that might be seen as bad by people with that dangerous outguilding privilege. This mentality makes it even more difficult to create some tension and conflict between tethers, as there are people in the game that are so hell-bent on preventing cross-tether RP that other players shy away from it completely.
That they do this out of fear that their character's actions might be misinterpreted, or incorrect assumptions are made, which subsequently leads to an outguilding, is even worse. That is not the right way to foster a good RP environment in this game.
The option should always be to interact about all aspects of the issues at hand, creating a solid foundation for all decisions made during the process. Instead of making an assumption about a situation, confront and interact. Instead of keeping the RP with only the person connected to you/your guild/your tether, bring in the other party to get all sides of a story. If that is not your character's inclination, threaten with death! If there is cross-tether tension, and this struggle is allowed to be played out with all parties involved, it opens up for a world of possibilities that would be otherwise locked away if one party is simply blocked from all interaction.
No one should ever be allowed to dictate how someone else plays their character.
If they want to play a Carnifex that struggles with the concept of Slaughter, because the bunnies are far too cute, let them! Are they Carnifex material? Maybe not to you, but time will tell! Allow them to play that concept out in their own time. Allow them to enjoy it to the fullest until they are ready to make a decision, without clamping down on them and forcing a change too quickly.
If they want to play out the struggle of switching tethers, let them. If they want to play a slow learner, let them. If they break the law, RP about it and punish accordingly, but keep away from blowing that punishment or the threat of it out of proportion. If they want to struggle with emotional issues, let them. If you want no part of it, back away. If they see that you are not interested in that kind of RP arc, they will find a different audience, or drop it as they choose.
Enforcing a "higher standard" for certain people in the game, or forcing people into boxes or categories, will only hurt the environment in the end, because it leaves no room for nuance, no room for natural mistakes. This is especially true if people are not allowed the time to work through them in their own time afterwards, or if they have that underlying fear of a disproportionate punishment, like outguilding.
In short, don't threaten with outguilding, because you risk doing more damage than good for the game as a whole. It should be a last resort, if used at all. Try to help make the game more enjoyable to people by fostering the RP environment rather than shoot people down for doing something outside the norm.