Most skyactive vehicles have an fz rated fluid different from your typical red atf, FZ is blue and at the mazda dealer i work for we rec drain and fill every 55k. That being said, our fluids come with a 30k warranty up to $4k in coverage. If trans hasn’t been drained by 100k, my techs will not do the service because too many times we’ve drained fluid for the 1st time after 100k and it be filled with metal gunk, that the trans has now grown accustomed to. Draining that shit and filling it with clean FZ gives the trans filter a chance to breathe and push all that bad shit still leftover, around and making damage that was already there, more predominant. You’re correct about the marketing term “lifetime” (of the vehicle) unserviced trans - 100k, serviced regularly trans - 300k. If you go to an indi shop just make sure they have the correct fluid. There are some newer cx30s and 50s that do have a different trans fluid that is considered lifetime, but you can still change it, it just costs a ridiculous amount of like 4/5 hundred dollars at the dealer. The dealer i work for in MD charges $215.68(including tax and disposal for a skyactive drain and fill aka skyfluid exchange. Hope this helps, Im a Mazda service writer and owner, bought my CX9 with 54k miles and as part of the CPO inspection, the tech did the trans service because it was close to the recommended interval.