the point of software freedom is not enabling verification, but control of one's own computing. I'm not saying verification and thus RB is undesirable or not valuable, just that we can get software freedom without them. as long as you can modify and build the program against your own bootstrapped build of the library, it is not relevant for your software freedom whether a third-party binary depended on another undesirable version of the library, or whether that third-party build is reproducible. one may argue that, at least in some such cases, the resulting third-party binary is not freedom-respecting, because of the blobs it carries, but if you have software freedom, you can rebuild it and avoid relying on the blobs. in extreme cases, getting a freedom-respecting binary to run in freedom may require implementing a free compatible library.