You should not copy from CC-BY-SA datasets or map views based on the pre-redaction data; please treat this like you would any other incompatibly copyrighted map data.
Essentially we’re left with some new blank spots on the map, and can respond with the process we know and love. Use your favourite mapping techniques (can include a first pass sketching in stuff from bing yes), go explore and fill in the blanks.
We have an ever expanding mapping community. If we can explain to all these new folks about the joy of mapping your neighbourhood, try to lead by example, and help others learn, you’ll be amazed what can be achieved.