The Steel Wind Strike spell description says (XGtE, p. 166; emphasis mine):
You flourish the weapon used in the casting and then vanish to strike like the wind. Choose up to five creatures you can see within range. Make a melee spell attack against each target. On a hit, a target takes 6d10 force damage.
You can then teleport to an unoccupied space you can see within 5 feet of one of the targets you hit or missed.
The way I read this follows as such: it says "you can" do this, and therefore it is a suggestion rather than a requirement.
However, I know the intent of the spell is to be essentially teleporting after every strike. The intent was derived from a tweet from Jeremy Crawford, which may change my interpretation to RAW vs RAI:
If you cast steel wind strike, the spell doesn't make you invisible during its attacks. You do vanish from your starting location, as you start teleporting around the battlefield, but you blink into view as you make each attack and then teleport to your final destination.
Am I correct in my interpretation that you don't have to teleport next to a target after your last attack from the spell?
Please let me know how I can determine in the future the emphasis for cases such as this, with a citation from a book if possible.