freebsd stable - Jul 2016 - sed command does not behave equal from 10.3 to 11.0

On Wed, Jul 27, 2016 at 09:45:23AM +0100 I heard the voice of
krad, and lo! it spake thus:
> are you sure you aren't hitting a port or something?
Locale dependant.

% echo "abc_ABC.def" | env LANG=C sed -e 's/[^A-Z0-9]//g'
ABC

% echo "abc_ABC.def" | env LANG=en_US.UTF-8 sed -e
's/[^A-Z0-9]//g'
bcABCdef

(pre-branch -CURRENT)


-- 
Matthew Fuller     (MF4839)   |  fullermd at over-yonder.net
Systems/Network Administrator |  http://www.over-yonder.net/~fullermd/
           On the Internet, nobody can hear you scream.

On 27 July 2016 at 11:01, Matthew D. Fuller <fullermd at over-yonder.net>
wrote:
> On Wed, Jul 27, 2016 at 09:45:23AM +0100 I heard the voice of
> krad, and lo! it spake thus:
>> are you sure you aren't hitting a port or something?
>
> Locale dependant.
>
> % echo "abc_ABC.def" | env LANG=C sed -e 's/[^A-Z0-9]//g'
> ABC
>
> % echo "abc_ABC.def" | env LANG=en_US.UTF-8 sed -e
's/[^A-Z0-9]//g'
> bcABCdef
>
> (pre-branch -CURRENT)
>
The issue is that, under the same locale, the output is not the same
in 10.3 as 11.0. It sounds to me a bug ...