I haven't looked in a while and see the HMH videos on Youtube stopped two months ago. Are they being archived on another website, or was Casey taking an RSI break?

Casey was upgrading GPU - you can see why in last episode. Afaik there were some issues with CPU that's why everything is delayed. See these tweets:
https://twitter.com/cmuratori/status/910245851879976960
https://twitter.com/cmuratori/status/914618686304018434
https://twitter.com/cmuratori/status/917630005705793536