There was a CLAM meeting in early April about reaching out to the inactive (barf ) and he obviously thought of you. (A friend of mine had a couple of texts from "well meaning" jw's)
It's not sinister, just deluded.
Just don't write back anything which might be interpreted as negative towards the magnificent seven.
If you do write back I would ignore the content and say something like this ...
Dear XXXX
Thank you so much for writing to me. I really appreciate your loving concern and am writing back to let you know that everything is going really well in my life at the moment.
I well know things can change for better or worse and I often reflect upon life's purpose and my place therein and am so grateful for my relative good health and good friends.
Please accept my best wishes to you and all those you hold dear.
Warm regards,
YKBW
That'll mess with his head!