So that section was to outline the point that void (labeled chaos here) is fundamental to existence. Here is the full scan where we see Kenjaku states "sorcerers (those who can use CE), non-sorcerors, and cursed spirits,
all represent possibilities" which in the
next scan (the one you reference) we are given the visual motif of light flickering on a black background. When Kenjaku states he tried to "bring this forth" himself he is referencing his mixing between curses and humans which is why Choso is highlighted in that panel. So this would extend to ontology of the basis of life forms would have to due with the nature of reality (and we know this
extends to animals as well). This motif is something Gege does consistently when the manga addresses deeper ontological aspects.
For instance, making a
distortion in space time [2] reveals this same canvas of emptiness
While regular humans would just see Sukuna hanging around, Gojo is able to see past the material world and spot the
exact same canvas which houses Sukuna's and Megumi's soul to see how Sukuna was adapting to his domain. We see this previously when Yuji entered Mahito's domain and forced
their souls to interact, we see the same exact void pictured to visually depict this. Mahito also being the one to expressly claim that Buddhist scriptures were textbooks to controlling the soul
based on his readings of the Heart Sutra ( a
sutra which touches upon Sunyata) and mentions the monk can "feels souls in the dark".
Notably, when Mahito is on the verge of death we also
see this background, and then immediately afterward, Mahito expands his domain and we see this same
canvas hit Yuji and exclude him from the domain.
Gojo separately also discussed seeing "
the core of cursed energy" during his near death which gave him
enlightenment and immediate insight into how jujutsu works that he didn't have prior to getting shanked.
Finally, we see this blank Canvas again when Sukuna discusses how he bypassed Gojo's infinity, with our starry empty canvas once showing up explicitly as Sukuna mentioned
targeting "existence".
I believe that should establish Sunyata being fundamental to the verse. Now as to how that relates to barriers and these upgrades?
Tengen (a verse god tier who laid the foundations for Jujutsu while also preaching Buddhism side by side) discusses with Yuki that she controls "Sunyata barriers" all across her land. She discusses that
"any person familiar with barrier jutsu" would be able to configure it's structure to some extent, with particularly proficient sorcerers being able to straight up reality warp. The first clause would indicate that all barrier users can inherently
interact with emptiness, hence why they'd be able to do so in the Sunyata barrier (just more freely as shown by Kenjaku) despite never being there before. The second clause highlights the extent by which this emptiness can be formed with Kenjaku's
reality warping and
constructing reality (see circular definition) in there based on logical concepts.
The translator note on the page also directly highlights to use that the Sunyata concept comes from Buddhism and does indeed represent the foundational emptiness of reality.