This article is a bit bizarre in what the author seems to have expected, or rather not expected.

The 64 Ultimate is, as far as I know, an FPGA-implementation of an original C64. It is, for most intents and purposes, a C64.

So why are they so surprised that the original peripherals, like floppy drives, can be attached to it? The only special thing required for that is likely a level shifter on board (as the FPGA will hardly be 5V). And moreover, what's special about CRTs that it's so surprising that they can be attached as well? The output is bog-standard composite or S-Video, you can attach anything to it, just like to the original C64...

It's more interesting that it has an added HDMI output, Ethernet, and Wifi.