The fact they’ve said so little speaks volumes
I thought the same.
While I do believe they, like so many people, will be devastated by the loss, I don't think they've been as close to Matthew since Friends ended.
Friends has been over for longer than it was on TV and yes ten years is a long time to work every day with the same people and of course you develop friendships and some of those will develop into feeling like family.
But realistically Matthew was a troubled man, and that can be hard for people to be around. Yes, it's sad but also I think there's a public perception that they all should be super tight and close. Sadly I just don't think they were and now they're having to put out such a statement not for necessarily for themselves but for the benefit of the fans. I'm not suggesting they wouldn't have made comments on their own, but equally it feels as though their grief is being shared.
They're not Rachel, Monica, Joey, Ross and Pheobe grieving Chandler. They're Jennifer, Courtney, Matt, David and Lisa mouring a former colleague and friend, and I think people (no-one in this thread just people generally) need to remember that.
In the same way Matthew himself wanted to be remembered for more than just Chandler. We have to remember they are also more than their friends characters too.