I think though that both can be true, he does miss Megan and he is also using her for money. This is why I said he could be toxic, and honestly I'm leaning more towards toxic rather than badly advised. Her might also be saying he misses the other grandchildren but not on a forum that pays because who would pay for that.
The problem with either/or thinking is that people aren't like that. It seems fairly clear why he doesn't see his grandchildren, and he is definitely making money from Meghan but I don't believe that necessarily means he doesn't miss her as well.