The wrong doing would be a lack of due-diligence but there are so many clubs with the same question mark that singling City out would be discrimination(or some other such legal word). Also, the argument from the club's point of view would be it's hard to prove because a lot of companies are registered in Isle of Man(where an owner can nominate a shareholder in their place) and/or use the British Virgin Islands(to avoid tax).
Rabin did a thread which pointed to United's(and Arsenal's?) betting company sponsorship('s), after Nick Harris tried to make it City only story, based on their being 'no online presence' for the company. He seemed so excited and pleased with himself, at the time.
While some pointed out; China based companies have no legitimate access to western social media platforms because they are blocked by their country... Which makes looking for their online presence on those platforms in the first place, rather stupid, especially for an 'investigative journalist'.
The United one Rabin mentioned was Yabo, who later changed their name to HTH. It seemed to have no more than a placeholder website that was barely functioning, just like the City one.
Newcastle, Watford, Leicester City, along with Manchester United have been mentioned on a
Financial Time's video documentary they made in 2023. City weren't mentioned in that, surprisingly. I think it's because their focus was on Xela Holdings and it's connection to Suncity.
Along with the above mentioned clubs, I seem to remember Arsenal, Everton and number of other PL clubs made the list of clubs with questionable betting sponsors, in an article from a few years back. Maybe someone else remembers which paper/online outlet did that article.
Money laundering in the UK seems to be a far
wider reaching issue than just betting companies(crypto companies also being used) and football.