Probably better asked in the pistol forum, but I believe so, yes. It's a shoulder stock that the ATF says turns a pistol into a short barrel rifle. The company making this probably has a FAQ on their site and/or even an approval letter from BATFE stating that this does not make an SBR. It's certainly not a shoulder stock.
But it looks like they are not currently in business for some reason so maybe an issue came up https://halix.co/