Having gotten into Hololive and vtubers a bit late, (only a month or two before EN was announced) I have a very blurry understanding of Matsuri's relationships (platonic and otherwise) outside of this pairing.
That said, this pairing is so incredibly sweet. I usually find Luna's 0 year-old princess shtick a bit grating, but when these two are together they're so dang cute and sweet and adorable and precious and wonderful that it doesn't even register.