Currently the Sichuan-Gansu routing from Chengdu to Songpan- Zoige - Langmusi - Hezuo (Xiahe/Labrang) - Lanzhou is open. There is hiking to be done in all of these areas, and in some, horseback riding as well if you're into that. In the past few years when there was trouble in the monasteries, Xiahe/Labrang would be closed (for short periods) to foreigners, but as that's off a side road, usually the rest of the thru-route remained open. Occasionally if coming southbound from Lanzhou, there would be a checkpoint at Linxia or Hezuo that would turn foreigners around, but not from the other direction (going northbound).

I'm about to embark on another travel adventure an if things go per my current rough plan, will be going through this area southbound (backroad to Jiuzhaigou) in about 3 weeks. Probably won't do extensive multi-day hiking, but will do some day hiking and try to report on whatever I find.

Also, if you haven't researched Siguniangshan (Sichuan), you might do so. mnredfox was there last fall and posted a very useful trip report on this forum.

Minya Konka (Gongga Shan) area is reputed to be worthwhile, but also is well-known for trails that can be quite treacherous--probably an area best done with a buddy or small group rather than alone.