SBA (Single Button Assist) is like the GSE addon that makes 1-button rotation macros, so that would be the one it’s “replacing”
Hekili is just like old school flash cards from IRL school 
to show you what to push next.
There isn’t anything like that rn on the PTR.
Not that one couldn’t or wouldn’t be in the works, just that we haven’t gotten one yet.
The rotation assistant is more like Spellflash or MaxDPS that lights up spells on the actionbar.
So yea, rn they have analogies of GSE and Spellflash/MaxDPS
in case anyone is curious how to make use of the spellfash feature…
Go to a targetdummy
Right click it to start attacking it
as the spells light up move them to more linear position on the actionbar
i.e. Spell #1 move to first actionbar slot 1.
keep doing this until you have all your spells in a logical order for you.
also…yea, the current APL lists for some classes are terrible. Hope they get it sorted before release.