How do I keep I make sure we stay in contact without being intrusive?

[Justmuddlingalong]

DB was through visiting recently and opened up about how he really feels about his wife/marriage.
I didn't really pass comment, although I wanted to, and just let him tell us how unhappy he is.
It's been obvious to other family members for years, but he's quite deep so it was never mentioned.
He said he wanted to end the marriage as he's been miserable for years.
We said we'd support him whatever he decides and would be on the end of the phone if ever he wanted to chat, as he lives across the country.
Since he went home, I feel like he's distancing himself, perhaps he's decided to stay, which is entirely his choice, but I'm worried he's now regretting being so open and is not quite so chatty.
I would also imagine if his wife gets the slightest whiff that he's spoken about it to us, she'll want him to cut contact completely.
I'm worried about him but don't want to be intrusive.
Any words of wisdom?

Is his wife controlling? Why would she cut contact? You could pass on the number of the mens advice line: mensadviceline.org.uk/

He might feel a bit embarrassed he opened up so much.

She's very controlling. His friendships have dwindled because of either her behaviour when out in a group or not wanting him to go out without her.
She hates all his workmates and would cut him off from us in a heartbeat.
He's very quiet, hardworking and just wants a quiet life.
In their marriage that has never nor will be an option.

There’s nothing you can do. Try not to blame it all on his wife, there’s 2 sides to every story, I doubt your brother is perfect. Just continue with a normal relationship and make effort with his wife too if you’re concerned about being shut out.

I doubt I'll hear from SIL any time soon. She made a massive show of herself at the last get-together, being abusive and demeaning to DB.
I'm not blaming anyone, I'm always civil to her, but my priority is my DB's happiness.