Comment by imrehg

This feels like an edge case.

The "reasonable limit" is likely set based on experimentation, and thus on how much people post on average and the load it generates (so the real number is unlikely to be exactly "2000", IMHO).

If you follow a lot of people, how likely it is that their posting pattern is so different from the average? The more people you follow, the less likely that is.

So while you can end up in such situation in theory, it would need to be a very unusual (and rare) case.