Also Tiger and Bunny and Sacred Seven (well, the TV part of Sacred Seven, the movie reedit thingy was unsubbed), and a few of their boxsets of older shows like My-HiME and My-ZHiME. I'm pretty sure that Accel World is actually published on Warner Home Video rather than Bandai Visual, though.
I gather the main reason behind all this subtitling is that Bandai themselves funded updates to... I think it was Aegisub in order to make it output subtitles in the format that their disk production partners use for producing BD subtitles. Because all the subtitlers who do work for their international streaming partners use Aegisub to do their subtitling work, it's become pretty trivial for them to incorporate those subtitles on their releases.
The outliers here are Gundam Unicorn (which was a weird experiment in doing international simultaneous releases at Japanese prices), Yamato and Nunnally. I kind of wonder if they've somehow gotten metrics showing that the increase in sales for the shows they started adding subtitles to and figured it was worthwhile paying for the translation of shows not being show aboard.