In recent years, the biggest threat for Meta Platforms (META -3.59%) has been TikTok. Meta's response to that has been its Instagram Reels, which allows users to easily scroll through quick videos just as they would with TikTok. Now, if TikTok ends up getting banned in the U.S., Meta could stand to benefit on multiple fronts: More users moving onto Instagram, and more ad dollars coming its way.It could set the business up for some great growth opportunities, but it also reminds investors of a big risk facin ...