Not sure what UK Dictates but here in the states parts do need to be produced for X number of years after production run. If I'm not mistaken the M3W has the MX5 third gen transmission right? Well they only stopped making that vehicle last year.
Not sure if Mazda themselves produce the parts in house or if they have a supplier that manufactures to their spec. But this vehicle had in no way been missing from the market for long enough to even have NOS. That and given the overall popularity of the Miata/mx5 I don't think these transmission will ever be scarce.
