nah that's why they had the dialogue with arya and dondarrion in the show
don't really understand why book readers say LSH won't be in the show.
I spoiled myself on Wikipedia and never read the books but, show wise:
- they made a huge deal with Dondarrion coming back to life.
- the Brotherhood was tracking Arya the last time we saw any hint of them, chances are they were lead to the Twins and found Caitlin's body.
- the show hasn't been shy on showing the smashed, butchered, maimed dead corpses of main characters. We haven't seen much about Caitlin. Granted even Robb's wife wasn't shown being thrown in the river, but the fact the show runners have been cagey about the fate of the Blackfish and Edmure is weird.
- she is a very powerful character, connected directly with many key characters. Lots of plot knots could be unravelled by a character like her, and lots of twist could be pulled because of her.
- with Arya becoming blind and LSH not "sounding" the way she did before dying, plus the hatred of Arya for the Brotherhood and the hatred of Caitlin for Jon Snow (basically the only living son she has left, since in the show she thinks all her children are either dead or lost to her), there are quite a few strings that can be pulled to make the story as heart-wrenching as ever.