it definitely helps, but it is no guarantee. It probably won't have an influence on the value of his work in the immediate future. Look at someone like Swoon. She consistently shows in museums and has works in their permanent collections, but her pricing has remained steady.
I own two of Matsu´s pieces and saw this, one of my pieces is actually being loaned out for this show.
Can anyone give an idea how big this is for him, I mean, this is a museum, right? Would be a pretty huge thing here.
This is Matsu's second museum show but his first solo. Origo, I also had a Matsu piece I own loaned to the museum for his first show. It is really nice for the provenance of the work.
Like rico mentioned, this definitely helps but is no guarantee for price increases. Also, please take into consideration that this particular museum show is directly related to the Japanese Embassy and Matsu's cultural background so it may be a little bit different than some other situations. All in all though this is great for Matsu and his career and I think it is a testament to his talent and what may be in store for his future.