Even if the execs have said information, I believe it would be legal for them to pick a team to decide when to sell more stock, where that team doesn't have access to anything non-public.
The execs can then delegate the decision to the team without the knowledge, which would be legal (I think!).
Also, they can call a press conference, tell everyone the material inside information, and then sell the shares. This is completely normal: every company does when it has material non-public information and doesn't want to wait for the next quarterly earnings report.
I believe that is also tricky. In most companies, there are all kinds of incomplete and unreliable financial indicators mid-quarter. It's only when the accountants add it up and the end of the quarter and the auditors check it is it suitable for release to the public.
The incomplete information is considered "material non public info" which stops the execs buying shares, but it isn't considered reliable enough info for the company to publish without risk of execs being sent to prison for publishing false info.
I think it is still tricky. When the big boss assembles a team (which doesn’t happen normally) and asks “hey figure out whether we need to buy this stock”, it still could be construed as acting based on insider information.
The execs can then delegate the decision to the team without the knowledge, which would be legal (I think!).