Especially with the "headband" and the blonde hair, I thought she very much had the look of the Enchantress from the comics, so this makes all kinds of sense. (imdb.com lists her merely as "The Variant")
I would say her appearance here is better evidence for the narrative that the MCU is choosing to ignore the previous TV material since the Enchantress appeared on AoS along with Lady Sif.
Of course, if she's a variant from a different timeline, what happened on AoS wouldn't matter, though.