Unfortunately, they just implemented the system to get back your stuff from your house plot if the house decays. I am almost positive any previous loss of plot is not included in this.
Don't worry though, the server Genesis (the current live server) will be joined by a new server called Elysium. Elysium is a fresh start server and will surely make it so that Genesis will be ignored. So, the good news is you didn't really lose anything at all.
