Tiffany specifically mentioned ablation OR surgery in her second to last video, so ablation wasn't 100% confirmed. Tiff probably hoped it would be ablation because its less invasive. Ultimately the decision lays with whoever is carrying out ablation/surgery.
The happy happy happy act is just that, it is an act. She buggered off on holiday with Matt on the basis that she just wanted to forget about cancer for a few days. What actually happened is she spent most of her holiday talking to her camera and talking about her upcoming scans.
Tiffanys asked if that means she stage 4 and her doctors said yes, she is stage 4. Did she ask what that means for her? Probably not because she likely knows the answer, her disease is no longer curable.
I am all for positivity, all for someone believing that one day they will do a 'boomerang dance' and say "I am cancer free, I am cancer free", but there comes a point where patients need to either educate themselves or at least ask important questions to those treating her.
I'm unsure how she can make statements like "my surgeon saved my life", right after he's told her the scan unfortunately shows the lung nodule does appear to be cancer.