I know many people who would be so happy to have received that type of attention even if it is from people who you no longer care about. What did they have to say? You will never know. I refused to paint every active JW with the same brush that many do. Maybe some of them might have written things that could have indicated unconditional love or maybe some might be feeling the same as you and wanted to let you know.
It is definitely not typical as most here will tell you when they faded it became "out of sight, out of mind" but that is just my opinion and my reaction. They did much more than just send a text or make a phone call. They actually wrote cards and letters and even mailed gifts. I find nothing wrong with what they did and it seems like a very nice thing to do.