I've flown with a refitted A330 and both new A330E planes, but it's been years since I've flown an A340 (like over a decade, seriously). I was booked to fly one last weekend but a delay put my connection at risk and I switched to an A330 from ARN. I'll do some research and edit this post with what I find

EDIT: from what I can tell the four rows of plus indicate a legacy configuration. according to the magazine link in the wiki the new plus has 8 rows, which is my experience on a new A330E. That might not be the case for the A340 but I doubt it. Looks like the seatmap online is currently showing you an old A340 is assigned to your flight. Of course, YMMV