Matsumoto has always made jokes like this about how Hamada doesn't get slapped enough, Yamazaki doesn't get slapped enough etc. They all have done, ever since the first do not laugh batsu. Personally, I see it as Japanese humour and Matsumoto always wants to look vulnerable.
Saying that... He's become a bit of a jiji, always moaning etc. I have watched Downtown for around 17 years now and I've been surprised by how much everyone here reads into things that are said or done. Of course I may be wrong about some things so please don't bite if I am!
A lot of people believe that they won't do a No laughing thing every year. In my experience, Japanese people tend to let people know that it will be their last time doing something so I'm quite confident they will do a Batsu Game this year. I would put money on that it will be the final one, a HUGE hurrah potentially but that's just my personal opinion. I think the whole bringing License into many more of the episodes also says something.
The whole 'do Hamada and Matsumoto hate each other'. They definitely do not hate each other and I do think they play on the fact they are not great friends. I am sure they have some sort of a friendship still, it's just unthinkable that they wouldn't to me. But working with each other every single day, you probably wouldn't be that bothered to have dinner with them afterwards :P
From the text you've written, if I were to translate that into Japanese and into a way I believe Matsumoto would say it, it wouldn't sound as negative as it does in English. It's hard to explain but I really don't think he sounds as negative as made out to be.
But hey, I may be wrong so please don't bite my head off. I'm just saying what I think but I do feel that everything is still normal. The whole point for the segments where a lot of other celebrities come in is so that they get air time too.
Once again, I may be wrong but I am quite relaxed about the whole situation. I think Matsumoto has just become a bit more grumpy and I wouldn't be surprised if he is bored of the games but that is about it... a 52 year old getting hit in the arse for laughing for new years eve... That should say enough xD