Of course you didn't expect anything back for being a loving, caring and supportive mum SparklyGrandma as anyone with any common sense would realise.
None of us expect our children's eternal gratitude because we chose to have them in the first place, and did all that we could to be the best parents we could be. That said, we didn't expect them to completely walk out of our lives and in some cases, take their children our GC with them, and if that's not bad enough, tell outrageous lies in an attempt to portray us as awful people, in order to justify what the truth will never justify.
I wonder what it is about estrangement, about those of us who've lost AC and in some cases our GC, that brings out the worst in others. If I still had the relationship with both of our boys that I now only have with one, if I was being allowed to be a GM and Mr. S. was allowed to be a GF, I may not understand how parents who've done nothing wrong could find themselves cut out of their AC's lives. I might initially find it hard to believe that it could ever happen. But, I'm sure that if I'd read any of the heartbreaking posts on GN on this subject, I wouldn't entertain myself by deliberately mis interrepting posts and/or twisting what's been posted to try and make the poster look as awful as possible.
I'm pretty certain that if I did feel the need to enter into the discussion I would do so with respect and empathy. I would be thankful that I was not in this terrible position and be thankful for every moment that I got to spend with my AC and GC in the knowledge that others are not so fortunate.