Tradecraft hasn't changed much. It has been fairly well tested. Operational security and information security have not changed much... They have become more difficult with cell-phones and small internet connected devices.
I think another big difference and a subject that probably would be included in a redo is understanding how all of the modern data generating systems can reveal covert activity through the analysis of metadata and how to "hide in the noise" of this.
The geospatial correlation of burner phone to actual identity if one does not practice good sanitation as far as locational security when accessing wireless networks as an example.
Last time I tried to order a purism... I waited for 4 months and then took about a few weeks and multiple payments for a refund. Have they worked out their supply chain issues yet?
I like to think of bitcoin as the censorship resistant settlement layer on which payment networks/systems can and are being built (like lightning network, which just passed all tests). There are some pretty sweet video demos of lightning network/payment channels in action.
Don't forget that it's now possible to broadcast bitcoin transactions via satellite - without internet...