Ah, the forum's back.
As long as parts supply continues to be supported, it can't really hurt...
...but there will be a lot of model-specific parts for our cars which won't be available elsewhere. In view of the chassis, suspension and brake mods over the donor car, don't expect any parts support there from Mazda. Similarly gearbox and, presumably, clutch, as I don't think anything else in the FCA line-up has this drivetrain in this orientation - and particularly not anything similarly sporty. Obviously all trim is Abarth-specific too.
I'm used to classic BMWs whose obsolete-model support is pretty good, if sometimes slow. Not sure FCA will match them, though. The good part is that they still seem to be making the car in LHD, which will help.