I get why Disney would be reluctant to re-use him, even with a substantially-changed appearance, but the logical choice is Liam Neeson.

Same height, same build, same gravitas. They grew up less than an hour apart on the shores of Lough Neagh in Northern Ireland.

The introduction of Stevenson's character is an intentional homage to the introduction of Neeson's character in "The Phantom Menace."

It would be a cool way of honoring Stevenson to have his countryman play the character.

The writer of this article clearly has no idea what he's talking about. The Adepts of the White Current in the Black Fleet Crisis explicitly tell Luke Skywalker "The Current is not simply the Force you know called by a different name." In no way are the Fallanassi Force-s. The Fallanassi also do not possess weapons and choose death over combat (unlike the Jedi, they are true pacifists). Also, they explicitly state in the books that no Jedi or Sith could find the Fallanassi without the help of an Adept of the White Current. If the witches in The Acolyte were Fallanassi, then the Jedi would never have been able to locate them.