To my eye, pieces attributed to Banksy have a unique and appealing aesthetic, and the art generally is thought-provoking. He also has a knack for pushing all sorts of buttons. See his immigration piece in Clacton-on-Sea [1] for an example of all of the above.

A paint splash hastily thrown on his art is less compelling to me, on all these dimensions. Perhaps it’s a particularly well-splashed bit of paint, but even so, the closest it can really come to commentary is something along the lines of “Banksy works in a transient medium, and all things in life, including street art, are destined to be painted over” or perhaps “this, too, is art”. But at this point, that is a not particularly original bit of expression, and I’d just as soon have the Banksy on display.

[1] https://www.bbc.com/news/uk-england-essex-29446232