Mass exodus from Eikaiwa, sign to move on?

I started an Eikaiwa job at a relatively large chain at the end of last summer. Because I started in the middle of the school year, my contract only extends till the end of March. At the end of February/beginning of March, several full time native teachers will be quitting. There may be an additional teacher leaving as well but it’s unclear at the moment. Is this a sign for me to move on and tell them I’m not renewing my contract for April? Or can I use this as an opportunity to ask for a raise (long shot, pipe dream, I know). The only thing is that I really don’t want to look for new jobs but all signs are pointing to this being a bad environment to stay in any longer than I already have. Also I definitely DONT want the additional responsibilities that will come with losing a bunch of teachers.