Many small and electronic publishers are “mom and pop” organizations, and when sales drop or real life gets in the way, they may close their doors. This is why it’s very important that you read your contract and understand all its provisions before signing.
Contracts usually contain a clause that states if the publisher closes (the language in the contract will read something like, “in the event of bankruptcy, insolvency, or liquidation”), the contract will automatically terminate and the rights automatically revert back to you. This means if the publisher shuts up shop, you get your books back, and can republish them however you wish.
Some contracts might also give a time frame of inactivity, after which your rights will revert back to you. One publisher I worked with had this in the co
