... if you think that in the future some campaign will try to collect the majority of ex-CMs in a higher paying campaign.
The possible type of platform that can launch a campaign similar to Chipmixer is also a mixer but I doubt if they can pay equal to what Chipmixer did although they can, it's hard to match CM payout especially now that the competition is very stiff.
And one last question. The CM campaign paid for a maximum of 50 posts per week, while the rest (except Stake.com) pay for a maximum of 25. Do you think this will lead some people to try to build up an alt account so that in the future they can get paid for two campaigns for a total of 50 posts per week?
That's possible and it could be happening but it's hard to accumulate 50 good posts majority of it in the gambling section unless you treat it as a full-time job, signature campaign to accumulate free Bitcoin is still the best option, but you also need a full-time job because there's no permanent signature campaign.