I have been closely following everything with the 20Hz/60Hz debate recently with Overwatch. I, like many others, feel that the game desperately needs something better than the 20Hz tick rates currently being used client side. However, doing more investigation on this topic I have come across the following pieces of information:

https://youtu.be/nilBzupE4Cc?t=339

The time for clients to interpret updates from the server is dependent on FPS. Thus, running at 60Hz seems to require at least a ~16ms or less simulation time. However, when the FPS of the individual drops below 60FPS, the time to interpret the updates is now longer than the time for new updates to be received from the server, causing issues.

So, if that is the case it means that 60Hz is only possible if every player is consistently over 60FPS (or so it seems). Overwatch is certainly an easy enough game to play in terms of Hardware requirements, but it would be another thing that needs to be accounted for.

The simple explanation for this would be that that "SIM" in the network display is actually just showing the FPS and it is not related to interpretation of information from the server at all. However, the "SIM" values don't actually perfectly equate to FPS as can be seen in the video, so it seems like this may not be the case.

What does this mean for high tick rate servers? Well, Blizzard would first need to implement workarounds for when people are not maintaining the necessary 60FPS to account for simulation time. It is possible that this would result in changing some aspects of how the engine runs. It also may be why there are bugs in the "High Bandwidth" settings used for Custom Games causing them to crash. Other games certainly have ways of dealing with this type of issue, but whether or not it has been implemented yet in Overwatch remains to be seen, and until this is really addressed in-depth it seems like high tick rate servers may be a ways away.