On first glance, this new animation system sounds great. But, they will force this on EVERYONE. Once it gets into Phase 3, developers will not be able to opt-out.

In order for this system to work, everyone will have to change every single animation command manually.

This is an extreme and terrible amount of work for developers who could be spending time making things instead of sitting there, going back into every game they had and changing every animation because Roblox decided to add a useless, unnecessary update. 

What's even worse is that some developers have hundreds, sometimes thousands of animations. They wouldn't possibly be able to update every single one.

Roblox also didn't make this announcement very accessible, which will hurt developers who didn't know.

If we don't do anything about this, thousands of games will break, and the ones that don't will have developers wasting hours fixing it.

If Roblox needs to make this update, make it optional.

More information here: https://devforum.roblox.com/t/animation-engine-runtime-changes-and-fixes/1320674