Krakens definitely trying to push USDT over the edge by opening margin trading.
My 5c is that this will all workout fine for Tether in the end and the usual bunch of people with inside info will have made some good money out another creative interpretation of the latest money making trend in crypto land- over dramatise the latest news (block size debate, exchange banking issues), get cointelegraph etc to play along, wait for the weak hands to panic, collect their crypto at bargain prices.
In terms of the margin trading, if Tether is actually in trouble, that could help shore it up IMO. As for what is behind some of the strange responses I've seen on reddit from a Tether dev -- I have had similar thoughts as yours concerning the FUD manipulation being employed. I can only think of three reasons to make the statements I saw: either (1) Tether's really aren't backed up fully by reserve USD or (2) they are backed up by reserve USD, they just want to create enough uncertainty so they'll be a temporary Tether price drop that they can profit off... OR finally (3) Tether is fully backed by USD but they can't fully say they have the reserves because by making statements like that they could be exposing themselves to libertydollar type prosecution. I'm hoping it's #3, or at worst some of 2 and 3.