I'd like to think that Riot pushing the diver update back is a really good sign.

Tanks and divers have a weird relation ship because they share items and playstyle but with completely different goals. Divers want to get all up in the enemy teams face, particularly the carries. Tanks kinda want to do the same but they are mostly focused on keeping the enemy tanks off their team as well. When I see Riot deciding to rework tanks first I see a company that has seen some of the problems that its "class by class" update structure can bring. If Riot Had likely already decided to rework both classes at one point but they likely recognised that if they reworked diver first they would need to make substantial balance changes to them again during the tank update because their key itemisation will have changed. Its also really possible that riot redefining how tanks operate in the game will give them room in the power budget to make tank items less about shoving stats into your tank like a balloon and more about fight control/utility. Those item changes would have a big effect on the divers too and if they had a brand new play style that was balanced around those new items it would probably be a nightmare if they were changed, it may even force them to do another full rework. IDK i'm probably just being optimistic. :D