"Looking to expand" is not the same as actually doing it. And PSG don't even own the stadium - they are merely tenants.
In around 8 months from now Spurs new stadium will be hosting 27% more fans than PSG's stadium does, including the biggest single-tier stand in the UK. More importantly, the stadium will be state-of-the-art in every respect. And yes, I do think players and managers pay some attention to the home stadium that they'll be playing in ... not least because it will form a significant part of their lives whilst they are at the club concerned.
You are yet another poster who clearly hasn't done his homework before posting ... because Pochettino has several times cited the new stadium project as one reason why he loves being at Spurs. For example:
"I think it's amazing, beautiful, so difficult to find the words. I can say thank you to Daniel, because that dream is amazing."
"... I think it will be a dream come true"
"It is not only the facilities, it is how Daniel is driving that project. A few weeks ago, myself, Jesús and my staff were at the new stadium with Daniel and the architect, and you can feel that it is not just an empty structure – there is a soul and love; there is care in every single detail. That is what excites me the most.”
"I love to work and feel part of the project; to share and create something special. I feel very important at Tottenham, very comfortable and I enjoy the journey a lot. Today, I don’t think about a future elsewhere.”