Comment # 7 on bug 1031133 from Marketa Calabkova

And the answer was:

Ok, thanks, I'll close this then. I'd still very much recommend you
switch to the correct usage, because it would remove a warning that
might confuse packagers and users alike within your distribution, it
avoids potentially training them to ignore warnings, it makes the
upgrade more robust as the alternatives are not dangling for a period
of time during some package removals, and as you all are not too
bothered with this problem, making this a long transition would
(apparently) not be a problem by itself? 

Packagers would be confused much more if we started a long transition...