Often the new strategies top level players test on anonymised accounts are subtle tweaks in lines deep into / slightly beyond opening theory. Often these lines are slightly inferior to mainline but come with an edge due to the "surprise factor" making it harder for opponents to prepare. Each of these subtle tweaks will only arise in a small proportion of games (as only some of the time your opponent will play the line you want to test), so I imagine fingerprinting based on play style will still work relatively well.
