What causes MAP sensor failure?

On the first question, yes, however it's also possible that you drove over something or that there is already a puncture in the tire and that it leaked down in that time. I would get a tire pressure gauge and watch that tire or jack up that tire and use a spray bottle filled with water with soap in it to spray down the tread, the inner and outer bead areas and the valve stem. You are looking for bubbles which would show a leak.
As for what could cause a MAP sensor to fail. They are not a common failure item, but inside of them is a pressure transducer, basically a diaphragm connected to a variable resistor. The resistor can fail if it had excess voltage applied or if it cracked. The diaphragm can fail from constant movement. The connector can corrode, or the internal connections can fail. A common reason for failure with manual transmission is high vacuum. Say you are driving along at a high speed and decide to downshift and take your foot off the throttle. That produces a much higher vacuum than the engine normally does. The MAP should be designed to handle that, but bad parts do slip through. The other thing is that 9000 miles would also fall into an area where it could be what is called "infant mortality" That is because most parts fall under what is called the "bathtub curve" That curve says that there will be higher numbers of failures of parts both early and late in life with a long period of useful life in between for the parts that don't fail early.