The Heralds and the Shard Honor were the only two parties who were part of the Oathpact. Odium being bound to the Roshar System was not a direct result of the Oathpact but the Oathpact is part of it. 
After the Last Desolation, nine of the Heralds thought they abandoned the Oathpact, leaving only Talenel'Elin to uphold it. However, despite what they believe, all the Heralds are still bound to the Oathpact.
While at least some of the Oathpact still stands, it is unknown exactly how much remains.
- Prelude to the Stormlight Archive
- How many parties were there to the original Oathpact?
— Words of Radiance Daytona signing - Arcanum - 2014-03-19
- Is the fact that Odium can't leave Roshar a direct result of the Oathpact, or something else?
— Shadows of Self Chicago signing - Arcanum - 2015-10-12
- With the Heralds we know that there's only one left... one Herald that's still bound to the Oathpact--
— Salt Lake City Comiccon 2017 - Arcanum - 2017-09-23
- Is there any of the Oathpact still functioning because of Taln's continued participation?
— Theoryland - Oct 14th, 2013