Indexing Now is exactly the same as Indexing Soon - it means that a book has been assigned to an indexer. In theory this should mean that you will see the index go up in the next few weeks. However, with member indexers, some books are taking months to complete. We can't really complain since they are volunteers and we are delighted that they want to index their books. But it will mean that you may see a book with that status for a long time - if the book is older and not on a lot of Bookshelves then you know it is being member indexed.
Sometimes a newly published book may be hard to get hold of so may take longer. Some publishers are good about sending us review copies to index, others not so good. You would think that publishers would be falling over themselves to get their books indexed on EYB but sadly not the case. Though we are about to start a big push to cookbook publishers to get them to understand what a great opportunity this is for them.
There shouldn't be any books that were Index Soon before the release and now are Request Index - the only status change should be to Indexed. Are you sure it isn't just that several of your books have all been indexed? If you can remember any titles for books that you think this has happened to, let us know and I will investigate for you.