First off....welcome to the Forum.
I'm aware of that Ruger has released a Mini in the caliber you mention but no, I haven't bothered to actually look one over. That's mostly because, in spite of my best efforts while trying to get any sort of useful accuracy out of an AAC-branded Remington bolt action rifle in the same caliber, it turned out that I was mostly just beating my head against a wall. Fact is, I've got an old Winchester 30-30 that'll shoot rings around that thing.
Plus, when ya really think about it, unless one has a use for sub-sonic ammo and a can, what's a Mini in that particular caliber going to do that can't be done better with a "regular" Mini-30, or for that matter, even a Mini-14?
But hey, just because I'm not a fan of the 300 AAC/300 Blackout cartridge, don't mean that you won't be. Lots of folks seem to be having plenty of fun with it these days....so maybe you will too.
DGW