He's Virgo - hence "submissiveness", which is not really submissiveness, it is rather "service" Virgos naturally love to provide.
He's intelligent, grown up man who lived his live to his best, and he took his last train with T (wealthy young woman - in comparison to him), last train in sense of having kids etc. (I still think they should be having kids anytime soon, because he's just too old for that, and it is a bit irresponsible towards the kid to have such old parents)
So, since Virgos are intelligent, rational and analytical, he let her be, corona tit helped that, and decided it is good for him to try something new in his life. I don't think he's submissive at all.
She's Pisces, they love to accommodate thier partners, and T loves to accent that she "wears what she likes reagrdless of what F thinks", but she likes to wear all the stuff he likes to see on her. She's the one who will adapt more.
I don't think it's bad, or that it shouldn't be like that. We all adapt to each other, otherwise we wouldn't be able to function.
If F is giving up on anything, it is for sure something he values less than what he gets, IF he gives up anything at all.