Due to the preorder cycle, it will take 3-4 months for the feedback of difficulty to impact buying behavior. So difficulty continues ramping up way beyond your expectation, and prices in the secondary markers collapse. The overshoot might be moderated by a major supplier going bankrupt and not delivering but otherwise expect your year end prediction to be reached in July.
You're making assumptions about assumptions hereon buying behavior based on the huge price jump in Q4 last year. You can't automatically factor in that happening again, so as soon as the difficulty hits about 15000 x 10e6 the current (yet to be delivered) $3/GH rigs will never be profitable and it's not going to take a genius to see the trend,
The companies that have their own asics are in a slightly different boat but even they have to look at RI and they might not be quite so keen to load in capacity which might not make their ROI target.
Time will tell what approach is right, neither of us have a crystal ball.