I asked something similar before applying for Booster due to similar concerns. The answer I received was:

[quote=@Lord Wraith]
I'm going to say that the posting requirement is more of a guideline for supporting characters because you do make a good point in that there might not be a plot for them to jump into, however, there's definitely a stipulation if someone comes along and wants to make them a driving character that you need to move or get out of the way. We don't want to encourage people to camp on characters for the sake of claiming them either.
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