Sort of.
The idea is that underused talents would also get incremental buffs until they were chosen equally by the top 10%.
However it would still require you to recognize which talents to choose together to make the use of them all.
And since incremental talent buffs will still apply uniformly in PvE and PvP, in 5 man and 20 man, the algorithm for talent balancing (which would be an independent neural network operation from the proposed M+ neural operation), would also have to take this into consideration.
The best way to program this would be two ensure that at least two talent builds are optimal for PvE and at least two are optimal for PvP (which does not imply mutual exclusion).
The best way to isolate such unused talents would be to look at the top decile of that class and spec and ask “is talent X be used regularly in PvP or PvE 5man or PvE 20 man?”
If talent X is not used instanced PvP or M+ or raids, then clearly talent X needs some sort of help.
We would then have the Neural Network reach the following conclusion via similar cost function on talent usage (instead of completion rates for keys): “Since Talent X is in Row N of this talent tree, and PvE players already have diversity in Talents Y and Z in this same Nth row, then let us buff talent X for PvP, since all PvP players choose Talent W, and don’t choose talent X,Y or Z.”
So overall, you wouldn’t be able to choose any talents you want for any game mode, nor do we want that(since certain talents have strong synergy with others). However, being able to choose between at least optimal talent paths for the gamemode (PvP or PvE), would overall be healthier for all classes and therefore healthier for the game overall.
The change in talent X could be the proc rate, the cooldown, the duration or the raw output (it would seek the balance changes in these four categories until it was considered viable).