Short answer: learn2pvp
Long answer: if you would stop bumping and start thinking for a second maybe the fact that no one is doing it despite the huge community means it would not be that useful after all. If you play long enough you eventually learn the durations of cooldowns applied against your class, and based on your own ability cooldowns you will know how to time your counter-attacks or preventive defenses. And let's say you can track those cooldowns, what are you going to do with that information? Just because the enemy can use a cooldown means he will blow it right away again, so at best you will waste your own abilities early and that will please your enemy for sure. If HE knows how to play he may even count on that. PvP is just too intensive to spend time watching timers. It is quite different with PvE where mobs AI has limits and you can actually make use of as much information as you can, including cooldowns.
Conclusion: is it possible to do? Most likely yes. Is it that useful? Maybe, maybe not. Will someone do it then? Probably one day, unless everyone ignored you from the repeated bumping
