A friend of mine is working for and with Schwalbe. He is very resourceful and a tinkerer, the most nerdy (in a good way) biker I know. Rides with him turn the uphills into incredibly interesting and controversial discussions on nerdy bike topics. Tire compounds were the thing for many 2018 rides =)
He was closely involved with the development and testing of the new ADDIX compounds a couple seasons back and tested all kinds of attributes and behaviors of different makes and compounds both in the lab and on the bike.
If I sum up his findings (to my best ability) he stated that current soft compounds are massively better in varying temperature ranges than those from ten years ago. Like with car tires, wear and tear (knobs tearing out) will increase massively when you run winter tires in very hot temperatures. Also, summer tires will harden significantly below 7deg C.
Maxxis recommended the 60a tires because of knobs tearing with soft compounds in winter. At the same time, grip will suffer because the compound hardens. A soft tire will feel pretty close to a harder compound below zero. But there seem to be big differences for different compounds. Oil viscosity vs. temperature seems to be a great analogy.
In my experience you can feel those alleged differences at temperatures right around the freezing point of water or slightly above, when you have frozen soil, ice, mud and wet, slimy roots. Your super grippy tires will feel not that grippy at all.
Same trails, same tires, same rider and 5 degrees lower (everything's frozen solid) - you'll have loads of grip. (on BOTH soft and harder compound tires).
All that is pretty theoretical - I'll happily run my Maxxis 3c MaxxTerra or Addix Soft tires front and rear all year round. Swapping tires is a little bit messy with sealant and the 2.5 Shorty WT works pretty okay in almost any condition.