The funny thing is that after episode ...three, Rose was 100% prepared for death and 100% prepared to fight for her life, after the parting of the ways Rose was 100% prepared to throw her life at a (hopeless) situation to hold on to the Doctor and their life together, AND after Reunion and especially after The Girl in the Fireplace she was 100% prepared for being abandoned (it had happened at minimum 3 times already) and she was 100% prepared to give everything up to prevent it. But she was ready for it every single second of every day. An absolute madwoman.
That she managed to come back from another dimension? That wasn't out of character at all. It made a lot of narrative sense. That she then went back... Well in a way the argument was made that what made Rose and the Doctor impossible and caused the Doctor's commitment issues and general assholery was the Doctor's fear of the inevitable loss of her. So in a way it made sense. And Rose had accepted a new version of the Doctor once before - that also made sense (and the beat of grief over the loss was implicit - and there was no time for it - but it kind of was necessary explicitly).
But the traveling...I can see why RTD wrote a scene with a TARDIS cutting... But on the other hand, what seperated them wasn't Rose growing old and dying and the Doctor's running from her - it was the danger inherent to the travelling, the lives they lived, the danger that the Doctor exposed her to. So in a way it also makes sense to take the scene out if you want to imply they had a long happily ever after. But it takes the travelling out of their love, it takes a huge bite out of what made them, them. It took an even huger bite out of the Doctor! And so, it was.... All a bit strange and sour and uncertain and . It didn't help that Doctor2 did his suit up differently tbh.