I’m not a lawyer, but I found this article to be especially informative regarding issues of attorney client privilege as they pertain to the Cohen search warrants. Oddly, the article quotes, Andrew Napolitano, an outspoken Trump supporter, but he does seem to get right to the heart of the matter.
. . . it was the approval of the search warrants themselves that should terrify Trump. The best explanation, remarkably, came from Andrew Napolitano, a Fox News legal analyst. Napolitano explained that, under normal circumstances, communications between Trump and his attorney are privileged. But this privilege does not apply if there is “a serious allegation of illegal activity, by the lawyer with the client,” he said. [The emphasis is mine.]
Napolitano also says he believes Trump is Cohen’s only client.
In other words, it looks like there was sufficient probable cause to convince a judge that Cohen and Trump (assuming he is the “client” in question) may have committed a crime together. At least that’s my takeaway, but, again, I’m not a lawyer – and as @Pet_Proletariat mentioned, it would be great if someone who is a lawyer could weigh in with some analysis on the implications of these search warrants.
The article includes links to a video of the Napolitano interview – I would recommend watching it – a real eye-opener as to how significant these searches could be.