I wouldn't chastise anyone who wishes to reroll at this point, in fact now is the perfect time to do so. Every single class has been torn down and flipped in some way or another and it just may or may not be what you've enjoyed playing anymore and that's okay. For instance I currently main a fury/arms warrior for WoD and am making the switch to Enh shaman in legion as from what I've gathered so far it embraces many mechanically similar ideas from fury but with far less rng draw back and is something I would really enjoy. For example fury's WoD meat cleaver allows you to whirlwind and then duplicate raging blows dmg onto all enemies, this is being removed from legion fury BUT Enh has crackling lightning which allows lava lash to duplicate onto all enemies, pretty much the same thing and something I enjoyed from the fury warrior that I've found in a new class/spec.
I previously played a resto druid and really enjoyed being able to fill any roll but at the same time disliked how big of a change it was when I would switch as each spec is modeled on different classes mechanics, e.g cat to rogue, bear to warrior etc. What I'm trying to say is that right now is the perfect time to go out and look at what each class and spec brings to legion, you might find things you really enjoy are now all bundled into a single class as I have.
With such massive changes to all classes you can't really fault anyone for refining what they wish to play.
now if only shamans got bladestorm.