Removed as Co-Author for Resubmission I was part of a university project team, and at the end of the semester we decided to submit a review paper related to the topic of our project. Our advisers gave us feedback and made suggestions on our draft. We submitted our draft to a journal and many months later, one of my team members got a notification that our paper needed to be edited to respond to reviewer comments and resubmitted. However, he did not contact us until a few months later, when he said he thought we should not submit because the necessary edits were too demanding. However, when he went to talk to our advisers, some of them decided to continue working and resubmit. The other student did not let any of the other team members know, and told the adviser no one wanted to help him without consulting us.
 A month later, we were all notified that they were resubmitting that week and they needed our consent to remove us as co-authors. They have made very significant additions to our paper, adding more sources and detail to our claims and rewording the majority of it. However, the overall idea of the paper is quite similar and there are aspects of the paper that resemble portions we wrote. I feel it is quite ungenerous of them to cut us all out from being co-authors, when we wrote the majority of the initial submission, even if the final draft is quite different. Did they do the right thing?
EDITS
To clarify some points - 
The main issue is that they have to resubmit in a few days, so any changes in authorship need to be approved by everyone very soon. I agree that our adviser should be changed to first author, but there's no time to get everyone's consent for that, unless he can get an extension.
The adviser has not been hostile in any way and I don't want to make things too awkward, but I don't quite feel comfortable signing off on cutting us all out. 
I guess my real question is should I insist they include us? How much of the initial draft must be modified before you can just remove co-authors.
It is not ethical to remove you as co-author from a resubmission, if you contributed to the first submission and your contribution is still relevant in the resubmission. In that case, there seems to be a portion of the text in the resubmission that is a revised version of text that you wrote, so your contribution is indeed still relevant to the resubmission.
Do not agree to being removed from the author list. Don't let yourself be pressured to agree by an impending deadline. In most cases it is no problem to get an extension, even up to multiple weeks, on manuscript resubmission deadlines. Moreover, it should have been the lead author's responsibility to plan everything so that the deadline can be met.
If the importance of individual contributions has changed by the revision, it may indeed be appropriate to change the author order. That has to be agreed upon by all authors. The editor might also want to have approval from all authors for that change.
Start collecting evidence to support your claims. In the text from the first submission, mark which portions of the text or data have been contributed by whom. Collect earlier drafts and emails or other communication that further evidence these contributions. If you have the revised version, mark which portions in that are based on contributions you made earlier.
If the lead author does not resubmit to the same journal with you as co-author, try to keep an eye on other journals in the same area. They may just try to go to another journal with the revised version, where the editor will not be aware that the manuscript may still contain contributions of someone who's not listed as an author. If you see a publication with text based on your earlier contributions, but not listing you as an author, contact the editor with a complaint, and provide the evidence you collected.