I think that means our sun is the object with the deepest gravity well, out to about (1/1.12)*4.24 = 3.79ly away.
I think that means that there could plausibly be objects out to about 3.79ly away that are in orbit around our sun.
The object from the article is about 0.0019ly away, so there could be quite a lot of new most-distant solar system objects still to be discovered!
Alpha Centauri A has a mass of 1.1x the sun, and is about 4.37ly away, which would mean our sun's gravity well runs out at
(1/2.1)*4.37 = 2.08ly - i.e. any object in orbit 2.08 ly away would (even if affected by nothing else), fall into Alpha Centauri A's gravity well before completing a full orbit and therefore couldn't possibly remain in orbit around our sun.
If that's true (and I have no idea whether any of it is true), then I think 2.08ly must be an upper bound on the outer boundary of the Oort cloud.
EDIT: Ah, I'm thinking 2-dimensionally. Of course, something could be in a much larger orbit in a plane that doesn't go near Alpha Centauri.
I had always thought of the solar system ending with the planets with some ambiguity about the ort cloud
But thinking about it as a system influenced by the biggest gravity well makes a lot more sense
And yet, Voyager 1 and 2 have now "left the solar system" and entered interstellar space. It looks to me like the definition of what's part of the solar system is a bit squishy.