The replacement line from Mopar does not have a temp port on it. Mass Diesel sells a replacement line with the temp port. It's doubtful a dealership would use a line you purchased for a recall/warranty replacement. You also need to send Mass Diesel your stock line back as a core exchange.
You can use the accumulator test port on the right side of the transmission (in the middle of the trans, just above the pan - sticks out at a 45° angle) for a temp port, but it's not as accurate as measuring the temp. in the cooler line. As long as you understand this, and allow for some error in the reading (25-30° or so), it should be fine. If you do this, use a 1/8" close nipple and an 1/8" tee fitting. This will prevent the sender from extending too far into the transmission and possibly interfering with something.
Remove the 1/8" plug, and replace it with the nipple. Screw one end of the tee onto the nipple. The sender goes in the opposite side. Plug the middle port of the tee with the plug you removed from the transmission. Tighten everything down, but do NOT use any telon tape or sealer. This will gunk up the valve body.
-Tom