EVE General Discussion

The effects of similar past events can be used (with varying accuracy) to predict the effects of future events. That's how meteorology works, that's how tide forecasting works, that's how the insurance industry works, and so on with every kind of forecasting used.

This is different from the truism you're talking about (Past performance doesn't predict future results) which is looking at effects only to predict future effects (for instance, looking at the past stock performance of a company and trying to guess at its future performance from that) instead of analyzing past events to predict the effects of future events.

It's certainly possible that this Nerf will be unlike all the previous Nerfs in EVE's history and cause a significant drop in subs/PCU/ACU. Is it likely? Not unless there are some strong arguments for why this Nerf is different.