Fabricated or observed? I guess for it to be on the table, it has to be in a natural, non-manmade state.
The four new elements, all of which are synthetic, were discovered by slamming lighter nuclei into each other and tracking the following decay of the radioactive superheavy elements.
Like other superheavy elements that populate the end of the periodic table, they only exist for fractions of a second before decaying into other elements.
These are manmade, if I understand correctly.
Most of the transuranium elements occur "naturally," (a definition that only makes sense if we exclude humans from nature, which is a nonsensical idea) but their half-lives are so short that beyond plutonium they're very rarely (or never) observed outside of nuclear reactors or accelerators.
All that is necessary for an element to go into the chart is that it exist long enough to be reliably observed. For UUO, (118) the half life is believed to be <1 millisecond.