Dark elf vs High elf : Professional vs Citizen Levy

[TheDungen]

Maybe they'll change it to high elves get the extra horde rank without being horde cause they're so well drilled? But that would promote small high elf armies and sell them less minis which seems to be the opposite of the general direction the game is going in.

[Razakel]

That problem might solve itself, small units are vulnerable to artillery and heavy hitting magic. In that case the optimal number of High Elves per combat unit would probably increase rather than decrease.

[Shards of Basalt]

Established canon simply isn't an obstacle to Mike Lee, back on the old Black Library forums he said some really interesting things like how Malus's Warpsword of Khaine effectively was the Sword of Khaine and his explaination of the Dark Mother was confusing to say the least.
That's not to say he can't be an entertaining author, just don't try to figure out where his work fits into canon you can and will go insane.

[Craze_b0i]

When all spearmen where fighting in two ranks, they were fighting in three.
When all spearmen can fight with a max of four ranks, they'll fight in five.

I don't see the issue

Not saying there is an issue. I am just saying with all these additional fighting-ranks already available via the main ruleset they might decide to change the HE ability to something else.