The change is due at 125,000 miles or 11 years!
Mine is a 2013 and no where near that mileage.
(Probably not even my lifetime of ownership mileage wise).
So will “probably” do the change perhaps at 10 years, (while I still can) and also fit a new coolant tank.
On reading, they can be prone to split and cause untold engine damage.
I would assume due to the constant heat/cold and what they are made from etc etc.
They may/may not, but worth doing the job to be honest.
For you, I would buy the FL22 and give it to the garage doing the job, (if not a Mazda one) just to be on the safe side.
Nice car by the way and enjoy life. 
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Thermostat change too whilst doing the coolant.
I had the coolant changed on my last NC as it was due 10-11 years old, just over 12 months after the stat failed.
I’ve not really read about coolant tank failures, well not on this forum but are aware the odd few have failed somewhere in the world. Given that info I fitted a DaveFab tank to mine, an easy mod and can be changed with very little if any coolant loss.
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Roger that.
Thanks all. Mines a 2014 so I’ll leave replacing it until nearer the 11 year mark. It just needed a bit of a top up as it was on the main mark, a little deionised water sorted that out.
Thanks so much for all the advice