If you have more than one pending MaxPass and you cancel one, can you immediately make a new one to replace it? Or do you have to wait until the time stated on the last MaxPass you made? For example, let’s say I made a MaxPass reservation at 9am for Soarin with a return time of 12pm and it told me I could make another reservation at 10:30am. Let’s say at 10:30am I make a reservation for Toy Story Mania with a return time of 1pm and its says I can make another reservation at 12 pm. If at 11 am I cancel my Soarin reservation, can I immediately make a new reservation to replace it, or do I have to wait until 12 pm?
I’ve only had one experience (when MaxPass was fairly new- less than 3 months) where I (accidentally) tested anything close to this & the short answer is: you would have to wait. Since then, I haven’t ever felt it worth it to purposefully cancel FastPasses to further test it out your exact scenario (and I don’t think I’ve ever heard of anyone testing this out either since the potential risk to be out of a FastPass outweighs the potential return- getting a slightly different FastPass). And then, even if I didn’t have experience with cancelling a FastPass after obtaining it, I would be inclined to say you would have to wait as Disneyland’s system is only designed to keep track of what your “next available” time to pull a FastPass is & doesn’t track or have any regard to what you do with the FastPasses you already obtained.
In case you want a few more details, our accidental test went something like this… (I should also note that we hadn’t purchased MaxPass BUT the only difference that it would’ve made for this story is that we would’ve been trying to get the it’s a small world FastPass that I mention below from our phones rather than on the physical kiosk- free of charge). Anywho, we had pulled Matterhorn FPs for me to take our 2 kids that were tall enough. The passes weren’t immediate but they were good for within 20-30 minutes of being pulled. (The husband wasn’t interested in riding & was going to stay back & chill with the baby who wasn’t tall enough). When we came back to ride Matterhorn, my daughter decided she wasn’t up to facing off with a cranky yeti on a dark, bumpy tobogan ride so she decided to stay back with dad & the baby. I then decided that we should get FPs for it’s a small world to do immediately after Matterhorn. My husband was going to take the baby & daughter on teacups close by and I instructed him to first wait until he saw me & my son scan in for the FPs and then use our tickets to get it’s a small world for all of us. While I was still standing with my husband, I first cancelled my daughter’s FP since we had no intention of now using it. My son & I scanned into our FastPass, leaving them to grab it’s a small world FPs.
When we exited the ride, I returned to a very frustrated husband who had just barely secured the it’s a small world FastPasses because the system made him wait until the time on the initially pulled Matterhorn FastPass. Even though it was definitely cancelled (my husband pulled up the app to make sure he didn’t see it still lingering and it definitely wasn’t), every attempt to pull a FastPass was met with the kiosk spitting out a slip of paper saying she couldn’t obtain a FastPass because she already had one. My husband finally went to the Cast Member with the app pulled up showing them that she didn’t have a current FastPass, explained that she had been too scared to get on Matterhorn so we cancelled it & that me & my son were on the ride (so had scanned in) and he was successful in getting a next FastPass for both of us. The best they could do was tell him the system would’ve let him pull one if we had simply scanned my daughter’s FastPass with ours and that he had to wait. Since the FastPass wasn’t that far out, he was able to stick around a few minutes to grab it.
TL;DR: It’s not been widely tested so YMMV. In my closest experience, (cancelling a FastPasses to get a different FastPass) the answer was a big fat, no you have to wait.
I am avid user of MaxPass and as @lolabear_la has described, no you would not, if you cancel, then you simply lose that fp. If you are in that situation, you can always hope that the ride goes down and you score an anytime fp!