As common with alot of other airlines, the cabin crew have a standard turbulence PA, let them deal with the situation as they see fit. If the seat belt signs go on, then they do the PA, end of story. If you explained every bump and swerve, jolt and bang (most of which are ignored by pilots) you'd be on the PA every five minutes.
Generally, when we are trundling over the far east, nearly every flight has some pretty fair turbulence, especially with the CBs down that way, it's seat belts on, hold on tight, concentrate, reconfigure if necessary and order more coffee. I understand and am sympathetic to nervous pax, but I'm not going to be on the PA every five minutes interupting the films.
Back to question involved, sounded like you may have passed through someones wake turbulence, it does happen but there is nothing to be concerned about, you missed him didn't you?