I believe that 184 might have gotten a fair share of DDs by now
if not because of the stupid extension that LTA have given to the
old bendies.
The point is, despite the substantial de-registration of bendies
(some of which were formerly perms of 184), SMRT is still not very
proactive in testing DDs for bendy-flooded services (and those in
need of DDs but have not gotten it before either during their times
in SBST or they are newly introduced under SMRT) in the last two
years as far as I know. Even for those that currently got DDs, it
seem to me that they got it silently.