Hard to say definitively as it has been difficult to get a good feel of what been happening the last couple of years due to high summer water levels. Last year it was looking OK until the water cleared and the huge number of pinks just kind of took over. From that point on I did not see a single summer chinook either live, dead or any redds but before that they were around in reasonable amounts. My guess is they were displaced by the hordes of spawning pinks. Kind of like little dogs bugging big dogs until they disappeared either to heavy fast water where they were unobservable or they buggered off back to the Squamish. Hard to say either way.
The fall chinook were OK but not nearly as good as the year before. That being said, the fall reds were much more plentiful than in most years with the exception of 2010 when it was just stupid for them ( for the Cheakamus anyway).
The Ashlu is / was a bust and is on very hard times and is showing no recovery at all.
The Cheakamus is the best of all the tributary streams but the big question mark is : How many fish spawn in the Squamish mainstem. It is very large and very glacial so you just don't see or find carcasses.
If I had to make an educated guess , I would say most years the Cheakamus is holding it's own at a moderate level. Hope this helps.