Ha, that's another thing entirely, I missed the gitter link, and was talking about the OP's report only

.
Unlike fbset, fbdepth tries *really hard* to keep the rotation as-is, kernel shenanigans included (easier said than done ;p). I'd be curious to have a look at the crash.log on an affected system (since fbdepth will log everything in there)!
EDIT: Ah, and the messed up FBInk prints quite possible make sense in that context, I overlooked that, I'll have to think about how to handle that...