It doesn't necessarily mean it will, but it is the trend and it is not unreasonable to think that it is more likely to have a random power chart than a pick your powers slot. Sure for the eldar it would make sense in the fluff, but the rules go against the fluff with armies all the time for the sake of balance. So mix that with the trend already happening here, and it leads to a very convincing, but not certain, argument.
Also, just because the psychic powers follow a trend doesn't mean "all armies have the same mechanics", it is far more complex than that and you know it. There is no need to be hyperbolic here, especially with rumours.