An ironic choice of hypothetical given that SQLite's present ubiquity is a result of a very similar licensing rug-pull on the part of Berkeley DB, after Sleepycat's acquisition by Oracle.

And, in turn, bdb gained prominence on the back of AT&T claiming copyright on ndbm during the Unix Wars.

So there's a long history of this, and plenty of precedents which suggest that such a move would make very little money and would likely result in a better alternative quickly rising to take its place.

I suspect that Hipp understands this, and is unlikely to do anything of the sort.