Just a rumour but I guess it makes sense - I've a friend on a circuit committee ( he knows it's not "the truth" but for family & work reasons he stays in ) & he says that the WTBTS have told them not to book a swimming pool for next years one day assemblies as the plan is to have only one baptism a year at the main regional ( what they used to call "District" ) convention.
With the drop off in baptisms so that sometimes there isn't anyone baptised or just a handful , I guess this is inevitable. I remember going to a baptism a few years ago - we had hired a municipal 25 metre swimming pool and only one person ( a rather confused and scared middle aged lady who hadn't been in a swimming pool since her youth ) was being baptised - it was all something of a farce with the "worldly" staff looking on very puzzled at such an elaborate & expensive ceremony for one person. ) Also with both assemblies being one day with just short morning & afternoon sessions , I suppose it is sensible to ditch the baptism talk - it tends to be something of a snoozefest anyway at the end of the morning session. And of course it looks better when there are a lot of JWs getting baptised in one go.
But as I said - just a rumour - I haven't had this independently confirmed.