I kind of disagree with this for a couple of reasons:
1: Some players only can log on for an hour or less a day, so it's better for those to have a full hour of trading rather than being hopeful they can get a couple of trades over the 24 hour time limit
2: I know some people are very impatient when trading (I've known people cancel in like ten minutes) so you would miss out on lots of trades if you weren't online when they were sent
3: It would make moderators lives more difficult trying to keep up with when everyone's bumped their posts, also there could be confusion if someone's talking on their thread would this be counted in the bump?
I agree for the point it gives people more of a chance to see other threads but if people are desperate they can just go to the individual forums (i use those mostly when looking for trades)