8 I/O lines are not being used. In my mind this is a waste.
Where would you put them, given that an Uno form factor has ... 25 pins (20+i2C+SPI) and there is no current standard board format with 8 more pins than that?
WiFi2 uses most of them for talking to the on-board peripherals. I can only find one unused pin (PC03)
The (Microchip) "ATmega4809 Curiosity Nano" that Pert mentioned is NOT a version of the Arduino Nano, but rather the next step downward in "development board complexity" from the previous "Xplained Pro" and "Xplained Mini" development boards.
In particular, the Curiosity breaks out ALL of the 4809 pins, and includes a nEDBG chip (thus the "nano" label. There's EDBG (an AVR32), mEDBG (as used on Zero - an ATmega32u4), and now nEDBG (a SAMD21 ARM chip.) The Curiosity is rather huge - longer than an Uno. (Diagram showing relative sizes. The Blue rectangle is the size of the Curiosity Nano, the thing in the middle is an Arduino Nano.)
I had thought that the Curiosity would prevent Arduino themselves from offering a Nano-sized 4809 board, but I guess not. Perhaps it's just too large. (it does not fit very well in protoboards!)