I read this paper yesterday and found it interesting. Cationic nickel complexes are not new. They often used as polymerization catalysts and you'll often see them coordinatively unstaturated which makes the olefin coordination easier.
In this work, the authors synthesized four complexes in total (2 neutral, 2 cationic) and they showed some catalytic activity. They are not impressive but this is just a communication so, I am guessing there will be a follow up with improved yields and reaction conditions.