@akibaun
A lot of studios (including the big ones) are sending us craploads of content. There's already a massive backlog of JAV VR to process.
Since they're already online partially, I can say CasanovA (#3 or 4 VR maker based on monthly output) is sending over 100+ titles at a time.
The super big ones that will be on SLR in good time will start by sending a smorgasbord of top-selling content in Japan and from there going by how sales do they may stick to certain genres to send over or just send everything.
Per genres, I agree that on one hand weirder is better (see PetersMAX), but weird and unusual may get people's attention, but might not always lead to sales. It's a tough game.
Fun fact: right now there are like 250 or so JAV VR titles released a month across the entire industry. Among those, about 25% are shot by one production company and it's not a name anyone has ever heard here (no studio site or anything). We went to their office and were blown away by how big they are. Biggest surprise on the trip.
Fun fact 2: some studios are currently streaming-only at SLR. Not ideal for many reasons, but some of the streaming-only ones will switch over to allowing DRM-free downloads soon and ones that requested streaming-only that are not even on the site told us given time and good sales, they can consider allowing downloads. Studios want to make money, but they want to play it safe. DRM sounds safe so it's what they normally ask for, but it's not 100% required in the long run.