"Concatenation will no longer sort" wording is very inconsistent
### The wording in the update docs is (emphasis added):
In a future version of pandas `pandas.concat()` will no longer sort the non-concatenation axis when it is not already aligned. (...)

To keep the previous behavior (sorting) and silence the warning, pass `sort=True`.
**To accept the future behavior (no sorting), pass `sort=False`**

https://pandas-docs.github.io/pandas-docs-travis/whatsnew.html#concatenation-will-no-longer-sort

### But the wording in the `FutureWarning` messages is (emphasis added):
Sorting because non-concatenation axis is not aligned. A future version
of pandas will change to not sort by default.

**To accept the future behavior, pass `sort=True`.**
To retain the current behavior and silence the warning, pass `sort=False`

https://github.com/pandas-dev/pandas/blob/c4da79b5b322c73d8e61d1cb98ac4ab1e2438b40/pandas/core/indexes/api.py

It needs to be clearer that current default is still `sort=True` but will revert to `sort=False` in a future version.