In my experience, you can almost always replace a filter on a mature healthy tank and not miss a beat. Especially true for planted ecosystems where the filter isn't the end-all be-all for nitrification. The issue I see as being more likely in your scenario is putting the AC50 on the new tank. While a seeded filter will speed up cycling, it isn't always instant and you'll sometimes have NH4 spikes even weeks down the road. My concern for this happening is even higher because you're presumably moving it from a tank with inert substrate to a buffering soil. ADA tends to drop your KH to 0 and pH well below 7. I'm not sure if it's a matter of hardness or pH but there seems to either be some bacterial die-off from the parameter changes or they at least take longer to establish back to numbers that can convert your NH4 all the way to NO3. Plus ADA releases NH4 for the first 4-6 weeks typically. I think what you have in mind will work, but don't be in too big a rush to add livestock to the new 33 gallon tank.
Nothing good happens fast in an ecosystem.