Seems odd to include such trivial changes in the changelog, as nobody is likely to be interested in reading about them. This particular defcustom was recently introduced, that's why I considered altering its default an extremely tiny change.
As for the tests - I'll change the state of the problematic test to have expected-result :failed. Sorry about that. Btw, what's the value of listing test changes in the changelog? Seems to me that pretty few people would be interested in reading about such changes.