I think that is the main reason why I stopped working as an employee. I'm just lucky to be picked as one of the participants in a signature campaign that is running for a long time already.
I've been in campaigns that lasted for several years that ended with absolutely no warning at all. When a good campaign ends the market will be flooded with its participants looking to join another and will likely be picked over other users.
If your campaign dying will screw your finances then you should be planning for that. It could happen any moment. I've seen people saying their pay their rent with sig campaign payments. That's nuts.