Form the Elegoo Uno R3 product page under specifications
Has Microchip made an upgrade we don't know about yet? 
That's 20x faster than the Cortex M4 on the R4 board! 
Listing created using AI perhaps?
Not in an UNO form factor, but the Arduino Portenta X8 has an ARM Cortex-A53 core which I believe is actually more powerful than the A8:
Maybe a future product that leaked out? More likely an AI translation from some Chinese source material, I remember manuals years ago where presumably human translators did just as bad of a job.
Adafruit makes a rather powerful UNO form factor board, with an NPX iMX RT1011 processor:
Adafruit Metro M7 with microSD
That's ok, as long as the price factor doesn't change..
What's an order of magnitude among friends? 
Wow.
My phone costs half of that and it has Cortex A53 and A73 (and some other components like 108MP camera, Amoled display, battery and plenty of memory). 