Wyrd is like a tapestry of your fate/destiny. The cords of your future, so to speak. At least in a Nordic context.

Pay closer attention to the post - the forest. It just happened to touch the taint instead.

The meaning is slightly different in a fae context.

Viravain tried making the Taint stronger, and Isune tried making it prettier.  They didn't mean to do it to the Taint, they aimed for the Forest, they just missed.  I think Night realized this, as She is the only entity in the Forest that isn't blinded by Viravain, in one manner or another.  Perhaps the Wyrm saw it to, and went to their aid?  Or perhaps Night's aid.  Who knows.  It's cool either way.

Apparently, the goddesses had attempted to recreate the forest
itself, Isune who tried to instill beauty and Viravain who tried to
invoke greater power. However, because the visions of the goddesses were
warped by Kethuru, they did not touch the forest at all, although they
individually thought they were doing so

Scholars later discovered that 'wyrd' was a fae word that could be
loosely translated to mean "a powerful event which changes the course of
the Fates".

I think it's a clever way of addressing some of Glom's problems, while still maintaining it as opposed and distinct to Serenwilde.

It will probably lessen some Serenwilde characters' dislike towards them, while finally distancing the forest from Magnagora.

They wont get a new archetype, Infested will just go to Wyrden, and basically everything else will be the same.

Scholars later discovered that 'wyrd' was a fae word that could be
loosely translated to mean "a powerful event which changes the course of
the Fates". Viravain and Isune together created the Wyrd of Glomdoring,
made manifest by the Ebonglom Wyrdling, which had emerged from the
cocoon. Apparently, the goddesses had attempted to recreate the forest
itself, Isune who tried to instill beauty and Viravain who tried to
invoke greater power. However, because the visions of the goddesses were
warped by Kethuru, they did not touch the forest at all, although they
individually thought they were doing so. Instead, their magics only
touched only the taint itself.
Thus, the Wyrd of Glomdoring came to be, which transformed the taintitself. What has sprung in its place is nothing anyone could have
imagined or foreseen. The word "Wyrd" now only means one thing to the
fae: that which was once the taint which now rests in Glomdoring, where
the earth itself is wyrden and the repercussions are only just beginning
to be felt.

Sweet, so now we can have pages of speculation and flames, and find out everyone was wrong later on.

Nice event btw, glad I was online.

Sylphas never really hated Glomdoring to start with, and Shikari is one of his favorite gods, so this will be quite interesting.  Even more of a reason for me not to talk, because a lot of Moondancer Taint fanaticism already didn't sit too well with him.