I've mentioned this before and I've not seen it said in other places, aside from some Youtube comments requesting promos but there was a programming block predating Toonami that aired Dragon Ball Z called A.K.A.
A.K.A was hosted by Jackie Potatoe, a character that resembles Dexter from Dexter's Laboratory with an afro that aired weekday nights between 7 and 9pm showing a good selection of shows new and old (at the time) like the Banana Splits, Wacky Races, Hong Kong Phooey, The Perils of Penelope Pitstop, Help!... It's the Hair Bear Bunch!, Harlem Globetrotters, Cow and Chicken, Dexter's Laboratory itself, Freakazoid and had an original show called Cult Toons.

While no promos seem to have survived I do remember A.K.A aired Dragon Ball Z at one time, possibly around the time it premiered in March 2000 as I seem to recall watching a rerun of some of those early episodes with Raditz at 7.30pm after the 5pm premiere. Hopefully someone out there still has the promos, it would be another great find in the never ending search for the abundance of lost media out there.
Little history lesson but back in the 90s Cartoon Network shared a channel with Turner Classic Movies on cable packages in the UK and Ireland, so if you had one TNT replaced Cartoon Network at 9pm. Sometime in 2000 TNT was being replaced on such packages and as I recall more people were getting Sky Satellite packages, I know my family got one around this time, I was so excited to have Cartoon Network round the clock as we did for the brief period in 1999 we lived in the USA. As such I can speculate that when Cartoon Network became more widely available as a 24-hour channel they removed Dragon Ball Z from A.K.A's timeslots, not wanting the block to depend on the show (although you could argue that is exactly what happened to Toonami) as Dragon Ball Z was also shown at 9pm timeslots, perhaps even thought it was a better fit for the Toonami block, which we got later that year.
Does anyone else have any lesser known details about the broadcasts they grew up with they would like to share? Would love to hear any.