This is the announcement Pimax made.

After CES, our Pimax R&D team will move on to debug the headset and improve the algorithm and make sure software is ready before we start to ship anything.

Our project team will evaluate risks, and annouce the shipping plan for the first batch.

Then, our Pimax community marketing team arrange close demos with VR enthusiasts, and ship a very small batch to the leaders in Pimax community and volunteers before shipping larger volume.

This does not sound like a drastic shift in their original goals/timeline. I think these articles are trying to make a big deal out of "here is a status update". Pimax said they expect to do 5 or so prototype revisions before finalizing hardware... This is #5 and they are demoing it at CES for feedback from a large audience.

Refresh rate: Still high risk. We are exploring a new hardware solution for 85Hz and 90Hz, theoretically feasible. We will reach a conclusion in March.

I'm not reading this as a delay for the Kickstarter backers but more a potential revision they are exploring for consumer version that will be available after the backers orders are fulfilled.