Maybe, and maybe they don’t care as long as they benefit from promoting such services. I am of the opinion that it is not professional to make such a mistake, because if you provide a very serious service, then you need to be especially careful what you advertise within that service. Any user of this crypto wallet who becomes a victim of this scam bookmaker will surely become a former user.
I do agree with the bolded, and of this is just a bad case of negligence on their part when doing proper research, it doesn't make it much better, as how exactly can you trust their wallet if they can't do something as simple as checking someone's track record before advertising them. I personally never used mycelium wallet, but if I did, I would probably stop using them at least until this is resolved.
To be frank I'm disappointed to see the ads of 1xbit in mycelium, but I do not think that Mycelium is scammer just because of the ads.
Best case scenario is that they acted irresponsibly and didn't check properly. Question is do you trust companies like that with your own money.