Had a feeling they'd do it because they haven't mentioned Tysha in the show since season 1. I guess it just means that Tyrion's current dislike of Jaime in the books won't end up meaning much.. Or maybe he'll never meet Tysha again or something.
Earlier in the season I was worried they'd not kill off Shae and have her sort of take the role of Tysha, leaving on that ship across the sea and then her being the one Tyrion was always thinking about/wanting to look for, so at least they didn't end up doing that.