Yes I dont think thats the normal arrangement for your car and it could have been installed by a PO or possibly even Triumph themselves. It doesnt allow as much movement as the sliding joint type (but then not much is needed), isnt so prone to wear but may not be as robust (Ive only seen them on Herald models).
It would be surprising if the propshaft was exactly the right length so it doesnt surprise me the straps arent perfectly straight plus on the central sliding bar theres been movement so its been doing its job...
As the manual probably recommends I would make it a part of routine maintenance to inspect the straps closely👍