I said "a well maintained transmission"... you missed that part didn't you? I wasn't disputing the fact that the OP should get the pan dropped for cleaning/inspection because its condition/maintenance history is unknown... but my point still stands that on any well maintained one, it's pretty unnecessary unless you're OCD
there's plenty of Japanese (especially toyota) transmissions out there that just had 30k drain and fills all of their lives and last well past 250k until the car either wrecks out or rusts out or the owner gets tired of it and moves on
there's also evidence out there that some skyactiv mazda owners never touched their transmission at all, and it lasted well past 200k miles and much more beyond.. exceptional? maybe, but it wasn't just 1 person but a handful... will I put my faith in the "sealed for life" nonsense? no, I'll still regularly change the fluid, but I have faith it'll be fine with just timely drain and fills without needing to spend more time with a pan drop and filter change... you can leave that for domestics (almost all of which have no drain plugs) and their crappy transmissions
and all gaskets are designed for one time use... if you think/want to risk reusing a gasket, go ahead.. I wouldn't do it at all, let alone non-critical parts... it's not worth my time having to redo something just to save $20 on a gasket plus money spent on new fluids on a redo... you can argue that mazda "cheaped out" using RTV, but like I already said, it's been proven better and more reliable for decades with sealing pans, blocks, and cases with many manufacturers, even toyota back in the 90s where they weren't known for nickel and diming on engineering/production expenses... you might think RTV is cheap because you might be used to buying the crappy $10 consumer grade tubes at the parts stores, but what the factory uses and what you can buy from the dealer are leaps and bounds better... might look the same, but not the same in chemical composition, pressure tolerances, heat tolerances, chemical tolerances, and durability/reliability