OP, unfortunately you do not have any control over his decision making in this matter.
Best to congratulate him and wish him the very best and her of course.
Lots of positivity.
However, should he think that he and his new wife to be, are moving in with you anytime soon, you can definitely have a view on THAT.
I would remain calm and positive and ask him when he has plans to move out and experience living on his own before marriage, which IMO is invaluable for both men and women.
He may not have given any thought to such matters, and he needs to.
Last year my recently retired friend had a similar issue.
Her son assumed that his girlfriend from university and himself could move into her home and live there and work from home as it would save them so much in rent now that they were planning on moving back to his home city.
She had been so looking forward to retiring and having two working from home adults was most certainly not on her cards.
She had to be very clear on that point as her son had simply never considered an apartment as his parents had a nice well located home.
Whilst she would have accepted a brief period whilst finding an apartment, she had no intention of spending her new retirement tip toeing around her home whilst two people work from home.
They had been sharing in a house together in their university city so there was no need to assume that they could automatically return home.
She loves to welcome them for sunday lunch, the odd mid week meal, etc., but living with her, no.
Some might think that harsh but I think that is her choice to make.