Hi
As far as l know, the cities are still there. I believe they are set to "abandoned" after a year of inactivity so that another mayor can claim them. So, if you can remember the server and city name of your old cities, you should be able to reclaim them as long as no one else has claimed them and is still actively playing.
The challenge for me would be remembering where they were and what they were named. If you remember, then search the correct server for the city name and see if it comes up. Good luck!