Purge community membership lists when community is deleted

[rahaeli]

Title
Purge community membership lists when community is deleted
Short, concise description of the idea
When a community is deleted, first purge community membership lists, so that situations such as this (it's happened before and I just spent 20 minutes looking for the other support requests, which of course now I can't find).
Full description of the idea
Currently, a community maintainer can delete a community while people are still subscribed to that community. Users are then left with no way to leave the community, as the community leave URL is dependent on the community ID #, which cannot be obtained while the community is deleted. Users can still remove the community from their friends listing, by using the admin console, but cannot leave the community and remove it from their "shared journal access" list. This causes headaches, upset users, and support requests, all of which are bad things. Either communities with members shouldn't be deletable, or deleting a community should first purge membership lists to avoid this situation.
An ordered list of benefits

Fewer support requests

Fewer "dead" communities in shared journal access lists

An ordered list of problems/issues involved

The usual argument about whether or not communities should be deletable might start up again. I'd feel really bad if that happened.

Someone might delete a community and then undelete it, thus purging the membership roster, and everyone would have to re-join.

An organized list, or a few short paragraphs detailing suggestions for implementation

Honestly, I think that just purging the membership lists before setting the community status to 'deleted', or purging the membership after the 30 day grace period, would be the best way to handle it.