That seems incredibly brittle due to making assumptions about the ID format that twitter has no obligations to keep. It just so happens that if your logic had been if(newId > olderId) you would have survived their new format (due to the fact that the timestamp leads the integer) but that'd be a win based on pure luck. The example the engineer came up with was seven years old so it had no way of foreseeing the ID format change.
It's a good point but I would suspect that the timestamp being prefix is no accident. If your IDs were sortable in the past it's probably a good a idea to keep them sortable. And since tweets more often than not refer to tweets in the same time range or are paginated together with tweets in the same time range (roughly) having time as a prefix has other advantages
