No - it's temperature monitoring of a NMC lithium battery. Nothing to do with what it's going into.
Any build is ultimately the builder's set of choices.
You can choose not to do it, just like you chose not to liquid cool it, then chose to put it in a closed box like the big boys do, but with no conductive heat path out. You unintentionally insulated an exothermic chemical reactor.
Does the Lithium battery in (most) Nissan Leaf(s) have (any) pack cooling?
...& are they mounted "in an enclosed box"?
...& they power full size (highway driven) cars?
* Concept,
Enclose the battery pack
...& most, if not all, of the high voltage stuff "safely" inside of a metal box (like most OEM EV's do)
1.) So, most (if not all) of the high voltage "stuff" is safely "sealed away"
...& isn't easily accessible (accidentally touchable) by you, family, friends etc. while on display
...or showing
...&/or even during general vehicle maintenance
2.) Again, so most (if not all) of the high voltage "stuff" is safely "sealed away"
...& isn't easily accessible by you, family, friends, first responders etc. in the event of a collision
3.) As a "Fire Wall" to help shield the vehicles occupants from "the battery pack"
...& (hopefully) give them a bit more time to exit, the vehicle, in the event of a fire
So, I thought this build would be a good example, to show folks, how someone "can" evaluate "a" situation
...& then, (how I went about) build an enclosed box
...that can hold the battery (pack) & associated "stuff"
...& then, (how I went about) mounting it, to the vehicle
&/so,
I intentionally put "this" NMC Lithium battery module, in a closed box "like the big boys" should do (but, not all do)
...for the reasons listed above

&
I intentionally chose to eliminate the liquid cooling system
...because IMO it's not needed, for "this" specific application
...will ultimately "serve no purpose"
...& just unnecessarily complicate "the build"
Your motorbike had 50mph air cooling - this has nothing at all because of the choice of using a closed, air insulated, box.
The (2) Chevy Volt module(s) on my ElMoto are "butted" right up against each other
...& almost completely wrapped with (the same) 18g. steel (except top & bottom)
...&/so, "if" your claim
"Your steel box will do nothing for cooling unless you couple it to the plates between the cells. The air space between the battery and the box will be a thermal insulator." is true
...then, my ElMoto doesn't have 50MPH air cooling
...& still doesn't (ever) warm up
...even when ~50A (~1C) steady & sometimes well over 100A (~2C) are being drawn from it