Q: alternator replaced 2 weeks ago and now transmission fluid bubbled and leaked all over the drive

Replacing the alternator does not implicate the transmission. These are completely unrelated vehicle systems. I suppose it is possible that a Mechanic could have added fluid, and to the wrong level, without your permission. Overfilling, as well as under filling, can cause problems with shifting. If it was overfilled, really only the excess would have been forced out; that is, overfilling does not necessarily cause the transmission fluid to completely empty itself out. Sometimes fluid can be forced out if the breather holes or assembly is blocked in the transmission, perhaps combined with overheating. In your present circumstance, the best thing to do is first clean up as much of the mess as possible, so you don’t have burning fluid under the hood and also to make it easier to inspect the issue. Then, check the fluid level, using the right procedure, and see where you are. If the fluid level is OK at the moment, try operating the vehicle and see if the issue recurs. If you still have a leak, obviously it will have to be tracked down and, as noted, the possibility of the breather being obstructed has to be considered. If you do suspect a leak, I recommend you request a transmission leak diagnostic which will provide a resolution of this issue for you.