Question I had the article doesen't address:

Does the JWST increase the size of the observable universe? No, it does not. The observable universe (OU) is limited due to the expansion of the universe, and some objects travel away from us faster than the speed of light.

The JWST is a near-infrared telescope which means we can see more objects that are redshifted beyond visible light. The JWST can see further into the distant OU than were possible with Hubble because hubble was designed mainly for visible light and its infrared detection is limited.

Does this mean the JWST can see the very furthest observable objects in the OU? No, it only allows us to view starlight that is redshifted into infrared wavelengths. This is practical to do with a reflective optical telescope because near IR wavelengths are short enough to be detectable with photoelectric stimulation of a semiconductor (think tiny solarpanels) which happens at the atomic level. There are yet "visible" objects more distant that are traveling away but emit light redshifted into the millimeter and radio spectrum that are theoretically visible with a moon-sized radiotelescope. The most distant objects' light in the OU are shifted into the VLF and TLF bands which would require a radio telescope larger than the galaxy to detect. We can be relatively confident there are galaxies beyond even the OU, which would render such a massive device useless in the search for evidence of the origins of the entire universe.