It was never announced or confirmed by any official staff that Deep Silver was the publisher IGA was working with. Someone had found that DS registered Bloodstained as a trademark, but they wouldn't comment about it. That trademark is the only link between the two, and when Ben Judd was asked about it at E3 by the Kinda Funny Games guys he said it was up to the publisher to make any official announcement. We were left with making an assumption without correction.
https://tmdb.eu/trademark/014052971/eu Koch owns Deep Silver.
Was DS actually involved and the source of the funding IGA mentioned in the KS video. I believe so. If so, they obviously didn't work out and we will likely not know the details due to professionals remaining professional. There are probably also written agreements protecting reputations as a part of renegotiating or terminating paperwork. Don't worry about DS owning any trademark though. (You're just gonna haveta trust me on that one.)
505 Games only has one black spot on their record, but they have many success stories. The developer for Payday 2 has blamed 505 Games for adding Micro Transactions to their game. The MTs were later revoked. I think there is more to the story and that 505 was used as a scapegoat, but I won't go into why unless asked. Ultimately, MTs in a Kickstarted IGAvania title that is under IGA's full control is simply not a concern of mine.
505 is legitimate. They aren't a huge evil publication corporation. I think they have about 100 employees according to their site. I hope to talk with them soon, but getting a hold of a PR manager of that Ian fellow might not be very easy.