I saw this locally. There are lots of groves in the area that have died or are dying now (probably greening) however I've had tons of new citrus plants sprout up out of nowhere for quite some time (various sizes and ages from seedling to 12'). Our grove never used ferts or insecticides and we were wiped out during the, freeze of 85/86 and the hurricanes in 04-05. Our last citrus tree was a blood orange which stopped producing in 2012 then died. (probably a 40-50 year old tree)
So I don't know.What I do know is development is claiming healthy groves at an alarming rate, while untended and dying groves often sit vacant.
Here are some photos I collected for a project I did for school I called "The Post Citrus Landscape"
Citrus Tower Clermont, FL
Today
Today