At the team owner her net worth is already in the Billions (3 Billion per Fox8). The only reason she would sell the team is if she doesn't want to be an NFL owner.
As for the impact, it all depends on Gayle's relationship with the Saints staff. This has been in the planning for years, so its not a surprise or unprepared for. We have not heard of any bad blood between Gayle or the Staff, as we did hear there was some between the staff and Rita.
As a functioning NFL franchise, I don't expect much to change for the foreseeable future other then they will probably honor Mr. Benson at every chance they get.