There is always time for that politics stuff......unfortunately.
I really doubt they will be lining up an Emissary and holding trials while a Titan and a Fomor army are attacking the city.
Now maybe immediately afterward... but I doubt it will be in BG at all.
Story-wise, it's not immediately relevant. The Svartalves can't go after him in Demonreach, and Harry and Lara don't yet know how to heal him so he can survive outside of Demonreach.
Thomas is not in "Christmas Eve", so I think he's still in Demonreach months later. This will probably be left for future books to resolve.
As far as the Svartalves know, Thomas mysteriously disappeared.
Once he pops up again, healed, *then* it's an issue (and Lara might be able to handle that).
And Swartalves are not known for letting thing’s slide. Nor is Harry a bully, he hates bullies.
Bullying, sure. But saying "if you want to kill my brother you'll have to go through me first" is
entirely in theme for him.
EDIT: finished/fixed sentence about "Once he pops up again"