May all be the case. However, to me it seems as if he was speculating on a move after this season but right now seems totally fine with staying. Before the Corona break, I was dead sure Sancho would be leaving after this season. I also could imagine that he'd strike his way out of Dortmund. But as his agent, I'd recommend him to wait another year now because it's the wisest thing to do for his career, especially given the renewed contract at Dortmund that probably earns him a lot already.
So yeah, I can imagine that he prefers England because he's homesick but if he's got many options on the table, who knows. Imagine a scenario in which four clubs are in for him and PSG is the only one meeting Dortmund's demands. If they tell him "listen, I know you prefer club x but PSG is willing to pay what we were asking for so if you really want to make the next step, we suggest you do it there". Then PSGs offers a tasty contract on top of that and that's that. This basically has happened with Havertz and Chelsea this season. He wanted to move on, only one club met the demands and off he went, although it was reported he use to sleep in Barca sheets as a kid and would be dreaming about Madrid currently.
I agree with your last paragraph for that reason. You really should've secured this deal this season, the next one it might be too late. Unfortunately, I think you had your chance for this window and now you have to beat the rest of the top dogs for his signature. I don't know if you could've paid the sum but didn't want to or if you really couldn't afford it in which case it was just bad luck but to me this becomes less likely every day.
By the way, thanks for the calm and polite discussion, is not necessarily a given in this thread
Don't you realize how shallow all this is while writing it? That's a whole lot of guessing and not necessarily logical conclusions.