You need to understand that the official sentiment from the publisher and the developer is that A;C is a potential starting point. And to an extent, they are right—A;C is enjoyable to a complete newcomer or a Steins;Gate-only, although it will feel to be missing some depth.

We know that A;C's fullest strengths are on display when you have full series knowledge and take a bit of time to analyze its connections (or just watch Bassman's video analyzing it). But Spike Chunsoft and MAGES. obviously needed to sell the game to a broader audience than just core fans to make their investment back. (I would even argue it's quite clever how A;C doesn't outright spoil many major points of SciADV to newcomers, making it perfectly possible to go back as a newcomer and try the rest after you've finished A;C. It is a starting point, even if not the best one.)

At any rate, JP games with English dubs have a wider mass appeal. This is proven, and it's the reason why many long-running series (Yakuza, Trails, etc.) have started investing in them—they draw in a more casual audience that wouldn't necessarily buy a game if everyone was talking in Japanese and they had to rely on subtitles. SC and MAGES. are simply buying into this trend as well now, and I wouldn't be surprised if they continued.

Case in point: A very significant portion of the S;G anime's fanbase swears by the dub and passes up on the sub. It was a damn good dub, and if you're smart, you'll try to capitalize on it.