Why have the servers been bad since like March?

I'm very curious about this.

I originally thought it was just because of the player count spike caused by sales, but I think the playerbase has somewhat stabilized by now, as it's been around a month. Unfortunately, the servers still seem to be somewhat derpy, slow, and unstable.

Not 100% sure if this is the issue, but Uber is in the process of migrating PA over from ubernet to pure playfab.

Yes, it's the migration to PlayFab.

The servers used to run on dedicated hardware (with overflow to VMs if capacity exceeded), and have been down-scaled to "VM-only" servers managed by PlayFab. (Which obviously don't fit, since they are too small for a game which performs the simulation on the server.)

Do I understand correctly that it's likely to get worse without getting better?

Mostly depends on how good these playfab servers are. For a game like PA, it's likely that it will be much worse.

It's all being done through AWS (edit: they're using azure) regardless, so I guess it just depends on how much money is being thrown.

It could also be argued which year?
2014?
2015?
2016?