This has generally turned out to be a problem very few people have. In practice, $bigCorp is happy to publicize all of the changes they make to this software.

This has generally turned out to be a problem very few people have. In practice, $bigCorp is happy to publicize all of the changes they make to this software. They can then focus on out-competing anyone by offering a cheaper and/or better integrated managed version then the original creators can. This is explicitly why Mongo moved from the AGPL to a custom non-FOSS license; Elastic followed suite and skipped the AGPL altogether for a similar license. Overall, $bigCorp love having any changes they make in upstream: less maintenance burden on them for the parts that are not in their direct business, more time spent on working on their value-adds.